All about the chemical element chlorine. Chlorine: Properties, Application, Receipt. The use of chlorine for industrial purposes

Chlorine - element of the 3rd period and VII A-group of the periodic system, sequence number 17. The electronic formula of the atom [10 NE] 3S 2 SP 5, characteristic degrees of oxidation 0, -1, + 1, +5 and +7. The most stable CL -1 state. Chlorine oxidation degrees scale:

7 - Cl 2 O 7, CLO 4 -, HCLO 4, KCLO 4

5 - CLO 3 -, HCLO 3, KCLO 3

1 - CL 2 O, CLO -, HCLO, NACLO, CA (CLO) 2

- 1 - Cl -, HCl, KCL, PCL 5

Chlorine has high electronegitance (2.83), manifests non-metallic properties. It is part of many substances - oxides, acids, salts, binary compounds.

In nature - twelfth By chemical prevalence, the element (fifth among non-metals). It is found only in a chemically related form. The third content of the element in natural waters (after o and H), especially a lot of chlorine in sea water (up to 2% by weight). Vital element for all organisms.

Chlorine C1 2 . Simple substance. Yellow-green gas with a sharp suffocable smell. CL 2 molecule is not polarized, contains σ-C1-C1. Thermally stable, non-combustible air; The mixture with hydrogen explodes into the light (hydrogen burns in chlorine):

CL 2 + H 2 ⇌HCL

It is well soluble in water, it is exposed to 50% dismutation in it and completely - in an alkaline solution:

Cl 2 0 + H 2 O ⇌hcl i O + HCl -i

CL 2 + 2NAOH (cold) \u003d NaClo + NaCl + H 2 O

3CL 2 + 6NAOH (mountains) \u003d NaClo 3 + 5NACL + H 2 O

Chlorine solution in water called chlorine waterThe NCLO acid is decomposed on the NHL and atomic oxygen about 0, so the "chlorine water" must be stored in a dark flask. The presence of nslo acid in the "chlorine water" and the formation of atomic oxygen is explained by its strong oxidative properties: for example, many dyes are discolored in a wet chlorine.

Chlorine is a very strong oxidizing agent in relation to metals and nonmetallam:

CL 2 + 2NA \u003d 2NAsl 2

ZL 2 + 2FE → 2FESL 3 (200 ° С)

CL 2 + SE \u003d SECL 4

SL 2 + PB → PBCl 2 (300 °FROM)

5Cl 2 + 2p → 2pcl 5 (90 ° С)

2CL 2 + SI → SICL 4 (340 ° С)

Reactions with compounds of other halogen:

a) Sl 2 + 2kvg (p) \u003d 2xl + in 2 (boiling)

b) SL 2 (week) + 2ki (p) \u003d 2xl + i 2 ↓

Zsl (rav.) + 3H 2 O + ki \u003d 6nsl + kio 3 (80 ° С)

Quality reaction - The interaction of the deficion of CL 2 with qi (see above) and the detection of iodine on blue staining after adding the starch solution.

Obtaining Chlora B. industry:

2NAsl (melt) → 2NA + SL 2 (electrolysis)

2NACL + 2N 2 O → H 2 + CL 2. + 2None (electrolysis)

and B. laboratories:

4nsl (conc.) + MnO 2 \u003d CL 2 + MNSL 2 + 2N 2 O

(similarly with the participation of other oxidizing agents; For more information, see reactions for HCl and NAcl).

Chlorine refers to the products of basic chemical production, is used to obtain bromine and iodine, chlorides and oxygen-containing derivatives, for whitening paper, as a disinfectant for drinking water. Poisonous.

Chlorinorrode NS. l. . Heavyless acid. Colorless gas with a sharp smell, heavier than air. The molecule contains a covalent σ-α-CL. Termically stable. Very well soluble in water; Diluted solutions are called chloride hydrochildo, and the smoke concentrated solution (35-38%) - hydrochloric acid (The name is also given by alchemists). Strong acid in solution is neutralized by alkalis and ammonia hydrate. A strong reducing agent in a concentrated solution (due to CL - I), a weak oxidizer in a dilute solution (due to H i). Composite part of the "royal vodka".

High-quality reaction to ion ion Cl - - the formation of white precipitation Agcl and Hg 2 CL 2, which are not translated into the solution with the action of dilute nitric acid.

The chloride is the raw material in the production of chlorides, chlororganic products, is used (in the form of a solution) when etching metals, decomposition of minerals and ores. Equations of the most important reactions:

Nsl (spz.) + NAON (spz.) \u003d NAcl + H 2 O

NSL (RSC) + NN 3 H 2 O \u003d NH 4 CL + H 2 O

4nsl (conc., Mountains.) + Mo 2 \u003d MSL 2 + SL 2 + 2N 2 O (M \u003d mp, py)

16nsl (conc., Mountains.) + 2kmno 4 (T) \u003d 2MNSL 2 + 5СL 2 + 8H 2 O + 2xL

14nsl (conc.) + K 2 CR 2 O 7 (T) \u003d 2CRSL 3 + ZSL 2 + 7N 2 O + 2xL

6nsl (conc.) + KSLO 3 (T) \u003d KSL + ZSL 2 + 3N 2 O (50-80 ° С)

4nsl (conc.) + Ca (CLO) 2 (T) \u003d CACL 2 + 2SL 2 + 2N 2 O

2NSL (RSC) + M \u003d MSL 2 + H 2 (M \u003d RE, 2P)

2NSL (RSC) + MSO 3 \u003d MSL 2 + CO 2 + H 2 O (M \u003d sa, va)

NSL (RSC) + AGNO 3 \u003d NNO 3 + AGSL ↓

Obtaining HCl in industry - combustion H 2 in CL 2 (see), in the laboratory - ousting from chlorides with sulfuric acid:

NASL (T) + H 2 SO4 (conc.) \u003d NanSO 4 + Ns.l. (50 ° С)

2NAcl (T) + H 2 SO 4 (conc.) \u003d NA 2 SO 4 + 2nsl(120 ° С)

Chlorida

Sodium chloride Na. Cl . Heavyless salt. Household title salt. White, weakgroscopic. Melts and boils without decomposition. Moderately soluble in water, solubility is little dependent on temperature, the solution has a characteristic salty taste. Hydrolysis is not subjected. Weak reducing agent. Enters the reaction of ion exchange. Subjected to electrolysis in the melt and solution.

It is used to produce hydrogen, sodium and chlorine, soda, caustic soda and chloride, as a component of coolant mixtures, a food product and a preservative.

In nature, the main part of the deposits of the stone salt, or galita, I. sylvinita (together with CCL), ramp of salt lakes, mineral impurities of sea water (content NaCl \u003d 2.7%). The industry is obtained by evaporation of natural pickles.

Equations of the most important reactions:

2NAsl (T) + 2N 2 SO 4 (conc.) + MnO 2 (T) \u003d CL 2 + MNSO 4 + 2N 2 O + Na 2 SO 4 (100 ° С)

10Nasl (T) + 8H 2 SO 4 (conc.) + 2kmno 4 (T) \u003d 5Cl 2 + 2MNSO 4 + 8H 2 O + 5NA 2 SO 4 + K 2 SO 4 (100 ° С)

6NAcl (T) + 7N 2 SO 4 (conc.) + K 2 CR 2 O 7 (T) \u003d 3SL 2 + CR 2 (SO 4) 3 + 7N 2 O + ZNA 2 SO 4 + K 2 SO 4 (100 ° С)

2NaCl (T) + 4N 2 SO 4 (conc.) + Pjo 2 (T) \u003d CL 2 + PB (NSO 4) 2 + 2N 2 O + 2NANSO 4 (50 ° С)

NaCl (RSC) + AGNO 3 \u003d NANO 3 + AGSL ↓

NaCl (g) → 2NA + CL 2 (850 ° С, electrolysis)

2NaCl + 2N 2 O → H 2 + SL 2 + 2NAON (electrolysis)

2NaCl (P, 20%) → SL 2 + 2 N.a (N.g.) "amalgam"(Electrolysis, onHg.- cathode)

Chloride potassium xl . Heavyless salt. White, non-hygroscopic. Melts and boils without decomposition. Moderately soluble in water, the solution has a bitter taste, no hydrolysis. Enters the reaction of ion exchange. It is used as a potash fertilizer, to obtain K, CO and CL 2. In nature, the main component (along with NASL) deposits sylvinita.

Equations of the most important reactions are the same with those for NASL.

Calcium Calcium Chloride 2 . Heavyless salt. White, melting without decomposition. Blinks in air due to energetic absorption of moisture. Forms CASL 2 6N 2 OH crystal hydrate with a temperature of dehydration 260 ° C. Well soluble in water, no hydrolysis. Enters the reaction of ion exchange. It is used to drain gases and liquids, preparation of cooling mixtures. Component of natural waters, part of their "constant" stiffness.

Equations of the most important reactions:

SASL 2 (T) + 2N 2 SO 4 (conc.) \u003d Ca (NSO 4) 2 + 2NSL (50 ° С)

CACL 2 (T) + H 2 SO 4 (conc.) \u003d CaSO 4 ↓ + 2NSL (100 ° С)

SASL 2 + 2NAON (conc.) \u003d Sa (it) 2 ↓ + 2NACL

ZSASL 2 + 2NA 3 PO 4 \u003d CA 3 (PO 4) 2 ↓ + 6NACL

CACL 2 + K 2 CO 3 \u003d SASO 3 ↓ + 2xl

CACL 2 + 2NAF \u003d SF 2 ↓ + 2NAsl

Casl 2 (g) → CA + SL 2 (Electrolysis, 800 ° C)

Getting:

Saso 3 + 2NSL \u003d CACL 2 + CO 3 + H 2 O

Aluminum chloride ALSL 3 . Heavyless salt. White, light-melting, severe. The pair consists of covalent monomers of the ALSL 3 (triangular structure, SP 2 hybridization, prevail at 440-800 ° C) and Dimers AL 2 CL 6 (more precisely, CL 2 ALSL 2 ALSL 2, the structure - two tetrahedra with a common edge, SP 3 -Hypebridization prevail at 183-440 ° C). Gigroscopic, the air "smokes". Forms crystal hydrate decomposing when heated. It is well soluble in water (with a strong exo effect), completely dissociates to ions, creates a strong-acid medium in a solution due to hydrolysis. Reacts with alkalis, ammonia hydrate. Recovered with melt electrolysis. Enters the reaction of ion exchange.

Quality reaction On ion of AL 3+ - the formation of a precipitate of the ALRO 4, which is translated into a solution with concentrated sulfuric acid.

It is used as raw materials in the production of aluminum, catalyst in organic synthesis and oil cracking, chlorine carrier in organic reactions. Equations of the most important reactions:

ALSL 3. 6N 2 O → ALSL (OH) 2 (100-200 ° C, -HCL, H. 2 O.) → ал 2 O 3 (250-450 ° С,-HCL, H2O)

ALSL 3 (T) + 2N 2 O (moisture) \u003d alal (OH) 2 (T) + 2NSL (White smoke")

Olcl 3 + znaon (spz.) \u003d Ал (ON) 3 (amorph) ↓ + znasl

ALSL 3 + 4NAON (conc.) \u003d NA [Ал (OH) 4] + ZnaCl

ALSL 3 + 3 (NN 3. H 2 O) (conc.) \u003d AL (OH) 3 (amorph.) + ZNN 4 SL

Olcl 3 + 3 (nn 3 H 2 O) (conc.) \u003d Ал (it) ↓ + znn 4 Сl + n 2 o (100 ° С)

2Al 3+ + 3H 2 O + CSO 2- 3 \u003d 2Al (OH) 3 ↓ + zo 2 (80 ° С)

2Al 3+ \u003d 6N 2 O + 3S 2- \u003d 2AL (OH) 3 ↓ + 3N 2 S

AL 3+ + 2NRO 4 2- - ALRO 4 ↓ + H 2 PO 4 -

2Alsl 3 → 2Al + 3СL 2 (Electrolysis, 800 ° С ,in meltN.aCl.)

Obtaining ALSL B. manufacturedand - chlorination of kaolin, alumina or bauxite in the presence of coke:

AL 2 O 3 + 3C (Coke) + 3СL 2 \u003d 2Alsl 3 + 3 (900 ° С)

Iron chloride ( II. ) F. eU l 2. . Heavyless salt. White (hydrate bluish-green), hygroscopic. Melts and boils without decomposition. With a strong heating of the fly in the NCl stream. Communication Fe - CL is preferably covalent, steam consists of FESL 2 monomers (linear structure, SR-hybridization) and dimers Fe 2 CL 4. Sensitive to air oxygen (darkest). It is well soluble in water (with a strong exo effect), completely dissociates to ions, weakly hydrolyzed by the cation. When boiling the solution decomposes. Reacts with acids, alkalis, ammonia hydrate. Typical reducing agent. Enters the reaction of ion exchange and complexation.

It is used to synthesize FESL and FE 2 O 3, as a catalyst in organic synthesis, a component of drugs against anemia.

Equations of the most important reactions:

FESL 2 4N 2 O \u003d FESL 2 + 4N 2 O (220 ° C, in atm.N. 2 )

FESL 2 (conc.) + H 2 O \u003d FESL (OH) ↓ + nsl (boiling)

FESL 2 (T) + H 2 SO 4 (conc.) \u003d FESO 4 + 2NSL (boiling)

FESL 2 (T) + 4HNO 3 (conc.) \u003d Fe (NO 3) 3 + NO 2 + 2NCl + H 2 O

FESL 2 + 2NOH (RSC) \u003d Fe (OH) 2 ↓ + 2NAcl (in atm.N. 2 )

FESL 2 + 2 (NN 3. H 2 O) (conc.) \u003d Fe (it) 2 ↓ + 2NH 4 Cl (80 ° С)

FESL 2 + H 2 \u003d 2NSL + F (especially clean, above 500 ° C)

4Fesl 2 + O 2 (air) → 2FE (CL) O + 2FESL 3 (t.)

2fesl 2 (p) + Sl 2 (Ball) \u003d 2fesl 3 (p)

5Fe 2+ + 8H + + Mno - 4 \u003d 5Fe 3+ + Mn 2+ + 4N 2 O

6Fe 2+ + 14N + + CR 2 O 7 2- \u003d 6FE 3+ + 2Sr 3+ + 7N 2 O

Fe 2+ + S 2- (RSC) \u003d FES ↓

2Fe 2+ + H 2 O + 2 2 2- (RSC) \u003d F 2 CO 3 (ON) 2 ↓ + CO 2

FESL 2 → FE ↓ + SL 2 (90 ° C, in RSC. NCL, electrolysis)

Receipte: The interaction of Fe with hydrochloric acid:

Fe + 2NSL \u003d FESL 2.+ H 2

(in industry Use chloride and lead the process at 500 ° C).

Iron chloride ( III ) F. eU l. 3 . Heavyless salt. Black and brown (dark red in the transmitted light, green in reflected), hydrate dark yellow. When melting goes into a red liquid. Very flying, with severe heating decomposes. Communication Fe - CL predominantly covalent. Course consists of FESL 3 monomers (triangular structure, SP 2-hybridization, prevail above 750 ° C) and dimers Fe 2 CL 6 (more precisely, CL 2 FESL 2 FESL 2, the structure is two tetrahedra with a common edge, SP 3-hybridization, prevail at 316-750 ° C). FESL crystallide. 6H 2 O has the structure of CL 2H 2 O. It is well soluble in water, the solution is painted in yellow; He is strongly hydrolyzed by the cation. Decomposes in hot water, reacts with alkalis. Weak oxidizer and reducing agent.

It is used as a chlorineent, a catalyst in organic synthesis, rubbing with tissue dye, coagulant when cleaning drinking water, a detergent of copper plates in galvanoplasty, component of hemostatic drugs.

Equations of the most important reactions:

FESL 3 6N 2 O \u003d CL + 2N 2 O (37 ° С)

2 (FESL 8 6N 2 O) \u003d F 2 O 3 + 6nsl + 9N 2 O (above 250 ° С)

FESL 3 (10%) + 4N 2 O \u003d SL - + + (yellow.)

2fesl3 (conc.) + 4N 2 O \u003d + (yellow.) + - (BC.)

FESL 3 (Spl., Conc.) + 2N 2 O → FESL (OH) 2 ↓ + 2NSL (100 ° С)

FESL 3 + 3NAON (RSC) \u003d FEO (OH) ↓ + H 2 O + 3NAsl (50 ° С)

FESL 3 + 3 (NN 3 H 2 O) (conc, mountains.) \u003d Feo (OH) ↓ + H 2 O + 3NH 4 Cl

4Fesl 3 + 3O 2 (air) \u003d 2FE 2 O 3 + 3SL 2 (350-500 ° С)

2fesl 3 (p) + Cu → 2fesl 2 + SUSL 2

Ammonium chloride N. H 4 CL . Heavy-minded salt, the technical name of the ammonia. White, volatile, thermally unstable. Well soluble in water (with a noticeable endo effect, Q \u003d -16 kJ), hydrolyzed by the cation. Decomposes with alkalis when boiling a solution, translates into a solution of magnesium and magnesium hydroxide. Connects a co-mutation with nitrates.

Quality reactionon the ion of NN 4 + is the release of NN 3 when boiling with alkalis or when heated with greased lime.

It is used in inorganic synthesis, in particular to create a weakly acid environment, as a component of nitrogen fertilizers, dry galvanic elements, when soldering copper and tinnitus steel products.

Equations of the most important reactions:

NH 4 Cl (T) ⇌ NH 3 (g) + HCl (g) (above 337.8 ° C)

NN 4 CL + NAON (saturation.) \u003d NaCl + NN 3 + H 2 O (100 ° С)

2NH 4 CL (T) + SA (OH) 2 (T) \u003d 2NN 3 + SASL 2 + 2N 2 O (200 ° С)

2NN 4 CL (conc.) + Mg \u003d H 2 + MgSl 2 + 2NN 3 (80 ° С)

2NH 4 CL (conc., Mountains.) + Mg (OH) 2 \u003d MgSl 2 + 2NN 3 + 2N 2 O

NH + (Out.) + No - 2 (Out.) \u003d N 2 + 2N 2 O (100 ° С)

NN 4 CL + KNO 3 \u003d N 2 O + 2N 2 O + KSL (230-300 ° С)

Obtaining: The interaction of NH 3 with HCl in the gas phase or NN 3 H 2 O with HCl in solution.

Hypochlorite calcium Ca (with l. O) 2. . Salt chlorinous acid nslo. White, when heated decomposes without melting. It is well soluble in cold water (a colorless solution is formed), hydrolyzed by anion. Reactive, completely decomposed with hot water, acids. Strong oxidizer. When standing, the solution absorbs carbon dioxide from the air. Is an active part chlorine (Belile) lime -mixtures of an indefinite composition with CAC 2 and CA (OH) 2. Equations of the most important reactions:

CA (CLO) 2 \u003d CACL 2 + O 2 (180 ° С)

Ca (CLO) 2 (T) + 4nsl (conc.) \u003d Sasl + 2SL 2 + 2N 2 O (80 ° С)

CA (CLO) 2 + H 2 O + CO 2 \u003d SASI 3 ↓ + 2NSLO (on cold)

Ca (CLO) 2 + 2N 2 O 2 (RSC) \u003d SACL 2 + 2N 2 O + 2O 2

Getting:

2s (he) 2 (suspension) + 2СL 2 (g) \u003d sa (CLO) 2 + SASL 2 + 2N 2 O

Chlorat potassium ks. lO 3 . Salt chlorinated acid NCLO 3, the most famous salt of oxygen-containing chlorine acids. Technical name - Bertolet Sol (by the name of its discoverer K.L. Bertoll, 1786). White, melting without decomposition, with further heating decomposes. It is well soluble in water (a colorless solution is formed), no hydrolysis. Decomposed by concentrated acids. Strong oxidizer when fusing.

It is used as a component of explosive and pyrotechnic mixtures, matches of matches, in the laboratory - a solid source of oxygen.

Equations of the most important reactions:

4xLo 3 \u003d ZKSLO 4 + KSL (400 ° С)

2xlo 3 \u003d 2xl + 3O 2 (150-300 ° С, Cat. MPO. 2 )

KSLO 3 (t) + 6nsl (conc.) \u003d Ksl + 3СL 2 + zn 2 o (50-80 ° С)

3xLO 3 (T) + 2N 2 SO 4 (conc., Mountains.) \u003d 2СLO 2 + KSLO 4 + H 2 O + 2KNSO 4

(Chlorine dioxide in the light explodes: 2ClO 2 (g) \u003d SL 2 + 2O. 2 )

2xLo 3 + E 2 (RI) \u003d 2KO 3 + SL 2 (in spz. nNo. 3 , E \u003d inr., I.)

KCLO 3 + H 2 O → H 2 + KCLO 4 (Electrolysis)

Obtaining KSLO 3 in industry - electricity of a hot solution of KSL (COPO 3 product stands out on the anode):

KSL + 3N 2 O → H 2 + KSLO 3 (40-60 ° C, electrolysis)

Bromide potassium kv. r. . Heavyless salt. White, non-hygroscopic, melting without decomposition. Well soluble in water, no hydrolysis. Reducing agent (weaker than

Quality reaction On Ion, the Criminal Procedure from the KVR chlorine solution and the extraction of bromine into an organic solvent, for example CCL 4 (as a result, the aqueous layer is discolored, the organic layer is painted in a brown color).

It is used as a component of etching agents for metals, an integral part of the photoemulsions, the drug.

Equations of the most important reactions:

2KVR (T) + 2N 2 SO 4 (conc., Mountains,) + MnO 2 (T) \u003d B 2 + MNSO 4 + 2N 2 O + K 2 SO 4

5В - + 6H + + in 3 - \u003d 3B 2 + 3N 2 O

Р - + ag + \u003d agvr ↓

2kvr (p) + Sl 2 (g) \u003d 2xl + Vg 2 (P)

KVR + 3H 2 O → 3N 2 + kVRO 3 (60-80 ° C, electrolysis)

Getting:

K 2 CO 3 + 2NVR \u003d 2kvr. + CO 2 + H 2 O

Iodide Kalia K. I. . Heavyless salt. White, non-hygroscopic. When stored in the light turns yellow. Well soluble in water, no hydrolysis. Typical reducing agent. An aqueous solution of KI is well dissolved by I 2 due to complexation.

Qualitythe reaction to Ion I is the outering of the iodine from the solution of the form of chlorine and the extraction of iodine into an organic solvent, for example CCL 4 (as a result, the water layer is discolored, the organic layer is painted in purple color).

Equations of the most important reactions:

10i - + 16n + + 2mno 4 - \u003d 5i 2 ↓ + 2mn 2+ + 8H 2 O

6i - + 14H + + CR 2 O 7 2- \u003d 3I 2 ↓ + 2CR 3+ + 7N 2 O

2i - + 2N + + H 2 O 2 (3%) \u003d i 2 ↓ + 2N 2 O

2i - + 4N + + 2NO 2 - \u003d i 2 ↓ + 2NO + 2N 2 O

5i - + 6H + + IO 3 - \u003d 3i 2 + 3N 2 O

I - + Ag + \u003d Agi (yellow.) ↓

2ki (P) + SL 2 (P) (week) \u003d 2xl + i 2 ↓

Ki + 3H 2 O + 3Cl 2 (P) (B) \u003d kio 3 + 6nsl (80 ° С)

Ki (p) + i 2 (T) \u003d k) (P) (Cor.) ("Iodine water")

Ki + 3n 2 o → 3n 2 + kio 3 (Electrolysis, 50-60 ° C)

Getting:

K 2 CO 3 + 2Ni \u003d 2 K.I. + CO 2 + H 2 O

Kuzbass State Technical University

Course work

The subject of BZK

Characteristic chlorine as an emergency chemically hazardous substance

Kemerovo-2009.

Introduction

1. Characteristics of Ahkh (on the task issued)

2. Ways to prevent accidents, protection against Akhov

3. Task

4. Calculation of the chemical situation (at the assignment issued)

Conclusion

Literature

Introduction

In total, Russia has 3,300 economy facilities that have significant reserves of hazardous chemicals. More than 35% of them have chic reserves.

Chlorine (lat. Chlorum), cl - chemical element VII group of periodic Mendeleev system, atomic number 17, atomic weight 35,453; refers to the family of halogens.

XLOR is also used for chlorination ne. OTO ryy ORDs for the purpose and attraction of titanium, niobium, zirconium and others.

Poisoning Chlorine is possible in the chemical, pulp and paper, textile, pharmaceutical industry. Xlore is annoying the mucous membranes of the eyes and respiratory tract. A secondary infection is usually attached to primary inflammatory changes. Acute poisoning is developing almost immediately. When inhalation of medium and low chlorine concentrations, constraints and chest pain are noted, dry cough, rapid breathing, turning into the eyes, tearing, increasing the content of leukocytes in the blood, body temperature, etc. Possible bronchopneumonia, toxic emotions, depressive states . In easily cases, recovery occurs after 3 - 7 days. As remote consequences, the Qatar of the upper respiratory tract is observed, recurrent bronchitis, pneumosclerosis; It is possible to activate tuberculosis of lungs. With prolonged inhalation of small chlorine concentrations, similar, but slowly developing forms of the disease are observed. Prevention of poisoning, sealing of industries, equipment, efficient ventilation, if necessary, using gas masks. The maximum permissible chlorine concentration in the air of production, premises of 1 mg / m 3. The production of chlorine, chlorine lime and other chlorine-containing compounds relates to production with harmful working conditions.

In the West of Flanders lies a tiny town. Nevertheless, its name is known to the whole world and will still be maintained in the memory of mankind as a symbol of one of the greatest crimes against humanity. This town is IPR. Cresses (in the Battle of Crescents in 1346 by English troops for the first time in Europe, firearms were applied.) - IPR - Hiroshima - Milestones on the way of turning the war into a giant destroyer.

At the beginning of 1915, the so-called IPRA protrusion was formed on the line of the Western Front. The Allied English-French troops northeast of Ipra wedged into the territory occupied by the German army. The German command decided to apply a counter and align the front line. On the morning of April 22, when smooth Nord-Ost, the Germans began unusual preparation for the offensive - they conducted the first gas attack in the history of wars. At the IPRA section of the front, 6,000 chlorine cylinders were opened at the same time. For five minutes, it was huge, weighing 180 tons, a poisonous yellow-green cloud, which slowly moved towards the enemy's trenches.

No one expected this. The French troops and the British were preparing for the attack, to the artillery shelling, the soldiers struck reliably, but they were absolutely unarmed in front of a destructive chlorine cloud. The deadly gas penetrated all the gaps, in all shelters. The results of the first chemical attack (and the first violation of the Hague Convention 1907 on the non-use of poisoning substances!) Were stunning - Chlorine struck about 15 thousand people, and approximately 5 thousand - to death. And all this - in order to align the front line of 6 km long! Two months later, the Germans took a chlorine attack on the Eastern Front. And two years later IPR entered his sad fame. During a hard battle on July 12, 1917, a poisoning substance named after an Iprit was first used in the area of \u200b\u200bthis city. Hyprint is a chlorine derivative, dichlorodiethylsulfide.

About these episodes of history associated with one small town and one chemical element, we recalled in order to show how the element number 17 in the hands of militant madmen can be dangerous. This is the most gloomy chlorine story page.

But it would be completely incorrect to see in Chlorine only a poisoning substance and raw materials for the production of other poisoning substances ...

History Chlora

The history of elementary chlorine is relatively short, it behaves since 1774. The history of chlorine compounds is old as the world. It is enough to remember that sodium chloride is a singers. And, apparently, even in prehistoric times, the ability of salt can serve meat and fish.

The most ancient archaeological finds - evidence of the use of salt by a person relate to about 3 ... 4 millennium BC. And the most ancient description of the extraction of stone salt is found in the writings of Greek historian of Herodotus (V c. BC). Herodotus describes the mining of a stone salt in Libya. In the oasis, sines in the center of the Libyan desert was the famous temple of the Ammona God. Therefore, Libya and called "Ammonia", and the first name of the stone salt was "SAL AMMONIACUM". Later, starting from about the XIII century. AD, this name fixed the ammonium chloride.

In the "Natural History", the Senior Pole describes the method of separating gold from non-dense metals when calcining with salt and clay. And one of the first descriptions of purification of sodium chloride find in the works of the Great Arabic Doctor and Alchemist Jabir Ibn-Heyan (in European spelling - Geber).

It is very likely that alchemists came across elementary chlorine, as in the countries of the East already in IX, and in Europe in the XIII century. The "tsarist vodka" was known - a mixture of hydrochloric and nitric acids. In the Book of Dutchman Van Helmont "Hortus Medicinae released in 1668," Hortus Medicinae "states that, with joint heating of ammonium chloride and nitric acid, some gas is obtained. Judging by the description, this gas is very similar to chlorine.

For the first time, Chlorine is first described in detail by the Swedish Chemist in his treatise about pyrolyzit. The heating mineral pyrolusitis with hydrochloric acid, Shelele noticed the smell characteristic of royal vodka, assembled and investigated the yellow-green gas, generating this smell, and studied its interaction with some substances. The Shelele first discovered the action of chlorine on gold and a cinnaker (in the latter case, Sullem is formed) and whitening properties of chlorine.

Shelele did not consider the open gas with a simple substance and called it "deflogistonated hydrochloric acid." Speaking by modern language, Shelele, and after him and other scientists were believed that the new gas was oxidized hydrochloric acid.

A little later, Bertol and Lavoisier were offered to consider this gas by oxidizing some new element "Muria". Within three and a half decades of Chemists, unknown Murius tried unsuccessfully.

Supporter of "Okisi Murius" was at first and Davy, which in 1807 laid out the electrical current to the table salt on the alkaline metal of sodium and yellow-green gas. However, three years later, after many fruitless attempts to get Murij Davy came to the conclusion that the gas, open Shelele, is a simple substance, the element, and called it chloric Gas or Chlorine (from the Greek χλωροζ - yellow-green). And after three years, Gay Loursak gave a new element a shorter name - chlorine. True, in 1811, the German chemist Schweiger suggested another name for chlorine - "halogen" (it is literally translated as Solerod), but this name did not initially be given, and subsequently it became common to a whole group of elements in which Chlorine also includes.

"Personal Card" Chlorine

To the question, what chlorine is, you can give at least a dozen answers. First, it is halogen; secondly, one of the strongest oxidants; Third, extremely poisonous gas; Fourth, the most important product of the main chemical industry; Fifth, raw materials for the production of plastics and pesticides, rubber and artificial fibers, dyes and medicines; in sixth, a substance with which titanium and silicon, glycerin and fluoroplast are obtained; On-seventh, remedy for cleaning drinking water and whitening fabrics ...

This listing could be continued.

Under normal conditions, elementary chlorine is a rather heavy yellow-green gas with a sharp characteristic odor. The atomic weight of chlorine 35.453, and the molecular - 70,906, because the chlorine molecule is Dvkatomna. One liter of gaseous chlorine under normal conditions (0 ° C and a pressure of 760 mm mercury pillar) weighs 3,214 g. When cooled to a temperature of -34.05 ° C, chlorine is condensed into a yellow liquid (1.56 g / cm density 3), and At temperatures - 101.6 ° C hardens. At elevated pressure, chlorine can be turned into a liquid and at higher temperatures up to + 144 ° C. Chlorine is well dissolved in dichloroethane and some other chlorine-containing organic solvents.

Element number 17 is very active - it is directly connected to almost all elements of the periodic system. Therefore, in nature, it occurs only in the form of connections. The most common minerals containing chlorine, Galite NACI, KCL Sylvinitis · NaCl, Bishofit MgCl 2 · 6H 2 O, Karnallite KCL · MgCl 2 · 6H 2 O, KIINIT KCL · MgSO 4 · 3N 2 O. This is first of all "Wines "(Or" merit ") that chlorine content in the earth's crust is 0.20% by weight. For non-ferrous metallurgy, some relatively rare chlorine-containing minerals are very important, for example, hornets AGSL.

By electrical conductivity, liquid chlorine takes place among the strongest insulators: it spends the current almost billion times worse than distilled water, and 10 22 times worse than silver.

The speed of sound in Chlorine is approximately one and a half times less than in the air.

And finally - about chlorine isotopes.

Nine isotopes of this element are now known, but in nature there are only two - chlorine-35 and chlorine-37. The first is about three times more than the second.

The remaining seven isotopes are artificially obtained. The most short-lived of them - 32 Cl has a half-life of 0.306 seconds, and the longest - 36 Cl - 310 thousand years.

How chlorine is obtained

The first thing you pay attention to, hitting the chlorine plant, are numerous power lines. Chlorine production consumes a lot of electricity - it is necessary in order to decompose chlorine natural compounds.

Naturally, the main chlorine raw material is a stone salt. If the chlorine plant is located near the river, then the salt is taken off by rail, but on the barges - so more economical. Salt is an inexpensive product, and it is consumed a lot: to get a ton of chlorine, it is necessary about 1.7 ... 1.8 tons of salt.

Salt enters the warehouses. It is stored three - six-month reserves of raw materials - chlorosal production, as a rule, multi-line.

Salt is crushed and dissolved in warm water. This piping brine is pumped into the cleaning shop, where in huge, height with a three-storey house tanks, brine are purified from calcium and magnesium salts and lightened (they give it to stand). The pure concentrated sodium chloride solution is pumped into the main chlorine production workshop - in the electrolysis shop.

In an aqueous solution, the molecules of the table salt are converted into Na + and Sl ions. Ion СL - differs from the chlorine atom only what has one excess electron. So, in order to obtain an elementary chlorine, it is necessary to tear this excess electron. It occurs in the electrolyzer on a positively charged electrode (anode). With it, as it were, the electrons are "sucking": 2cl - → Cl 2 + 2ē. The anodes are made of graphite, because any metal (other than platinum and its analogs), selecting extra electrons from chlorine ions, quickly corps and destroys.

There are two types of technological design of chlorine production: a diaphragm and mercury. In the first case, the cathode serves a perforated iron sheet, and the cathode and anodic space of the electrolyzer is separated by asbestospertic aperture. On the iron cathode there is a discharge of hydrogen ions and an aqueous solution of caustic soda is formed. If mercury is used as a cathode, sodium ions are discharged and the amalgam sodium is formed, which is then decomposed with water. It turns out hydrogen and caustic nat. In this case, the separation diaphragm is not needed, and the alkali is obtained more concentrated than in the diaphragm electrolyzers.

So, chlorine production is at the same time the production of caustic soda and hydrogen.

Hydrogen is discharged by metallic, and chlorine in glass or ceramic pipes. Freshly prepared chlorine is saturated with water vapor and therefore, especially aggressive. In the future, it is first cooled with cold water in high towers laid out from the inside with ceramic tiles and filled with a ceramic nozzle (the so-called rolling rings), and then dried with concentrated sulfuric acid. This is the only chlorine desiccant and one of the few liquids with which chlorine does not interact.

Dry chlorine is no longer so aggressive, it does not destroy, for example, steel equipment.

The chlorine is usually transported in liquid state in railway tanks or cylinders under pressure up to 10 atm.

In Russia, the production of chlorine was first organized in 1880 in the Bondyuzhsky factory. Chlorine was obtained, in principle, in the same way, how at one time he received his Shelele - with the interaction of hydrochloric acid with a pyrojit. All the produced chlorine was spent on obtaining chlorine lime. In 1900, a chlorine electrolytic production was commissioned at the DonSOD plant in Russia. The capacity of this workshop was only 6 thousand tons per year. In 1917, all chlorine plants of Russia produced 12 thousand tons of chlorine. And in 1965, about 1 million tons of chlorine were produced in the USSR ...

One of many

All variety of practical use of chlorine can be expressed by one phrase without a special stretch: chlorine is necessary for the production of chlorproducts, i.e. Substances containing "related" chlorine. But speaking of these chloroproducts, one phrase is not separated. They are very different - both by properties, and for their intended purpose.

To tell about all the compounds of chlorine does not allow a limited amount of our article, but without a story, at least some substances, for which chlorine needs, our "portrait" of the element No. 17 would be incomplete and unconvincing.

Take, for example, chlororganic insecticides are substances that kill harmful insects, but safe for plants. A significant part of the chlorine produced is spent on plant protection tools.

One of the most important insecticides is hexachlorcyclohexane (often called hexachlororan). This substance was first synthesized in 1825 by Faraday, but practical application was found only after 100 years old - in the 30s of our century.

Now hexahloran is obtained by chloring benzene. Like hydrogen, the benzene reacts very slowly with chlorine in the dark (and in the absence of catalysts), but with bright lighting the reaction of the chlorination of benzene (from 6 H 6 + 3СL 2 → C 6 H 6 CL 6) is quite quickly.

Hexachlororan, as well as many other insecticides, is used in the form of dusts with fillers (Talc, Kaolin), or in the form of suspensions and emulsions, or, finally, in the form of aerosols. Hexachloraran is particularly effective when the seeds are etched and when combating pests of vegetable and fruit crops. The consumption of hexachlor is only 1 ... 3 kg per hectare, the economic effect of its use in 10 ... 15 times exceeds costs. Unfortunately, hexahloran is not harmless to humans ...

Polyvinyl chloride

If you ask any schoolchildly to list the plastic known to him, he is one of the first to name polyvinyl chloride (otherwise, Viniplast). From the point of view of the chemist, PVC (so often polyvinyl chloride is denoted in the literature) - this is a polymer, in the molecule of which at the chain of carbon atoms "rod" hydrogen and chlorine atoms:

In this chain there may be several thousand links.

And from a consumer point of view, PVC is insulation for wires and raincoating raincoats, linoleum and grammplastics, protective varnishes and packaging materials, chemical equipment and foams, toys and details of devices.

Polyvinyl chloride is formed during the polymerization of vinyl chloride, which is most often obtained by treating acetylene with hydrogen chloride: HC ≡ CH + HCl → CH 2 \u003d CHCl. There is another way to obtain vinyl chloride - thermal cracking of Dichloroetan.

CH 2 Cl - CH 2 CL → CH 2 \u003d CHCl + HCl. The combination of two of these methods is of interest, when the HCl is used in the production of vinyl chloride on the acetylene method, which is used during the cracking of dichloroetan.

Vinyl chloride is a colorless gas with a pleasant, somewhat foxing essential smell, easily polymerized. To obtain a polymer, liquid vinyl chloride under pressure is injected into warm water, where it grows on the smallest droplets. So that they do not merge, slightly gelatin or polyvinyl alcohol add to the water, and the polymerization reaction began to develop, the polymerization initiator is introduced there - the benzoyl peroxide. A few hours later, the droplets solidify, and the suspension of the polymer in water is formed. Polymer powder is separated on the filter or centrifuge.

The polymerization usually occurs at a temperature of from 40 to 60 ° C, with the lower the polymerization temperature, the longer the polymer molecules ...

We only told about two substances, for which element No. 17 is required. Only about two of many hundreds. Such examples can be given a lot. And they all say that chlorine is not only a poisonous and dangerous gas, but a very important, very useful element.

Elementary calculation

When the chlorine is obtained by electrolysis, the solution of the cooking salt is at the same time hydrogen and caustic Natra are obtained: 2NACL + 2H 2 O \u003d H 2 + CL 2 + 2NAOH. Of course, hydrogen is a very important chemical product, but there are cheaper and convenient methods for the production of this substance, such as the conversion of natural gas ... But the caustic Natro is obtained almost exclusively by electrolysis of the solutions of the cooking salt - the share of other methods accounts for less than 10%. Since chlorine and NaOH production is completely interrelated (as follows from the reaction equation, the preparation of one gram molecule - 71 g of chlorine - is invariably accompanied by the production of two grams of molecules - 80 g of electrolytic alkali), knowing the productivity of the workshop (or plant, or state) on alkali , It is easy to calculate how much chlorine it produces. Each ton of NaOH "accompanies" 890 kg of chlorine.

Well, lubricant!

Concentrated sulfuric acid is almost the only liquid that does not interact with chlorine. Therefore, for compression and pumping chlorine at factories, pumps are used, in which the role of the working fluid and at the same time lubrication performs sulfuric acid.

Pseudonym Friedrich Völer

Exploring the interaction of organic substances with chlorine, French chemist XIX century. Jean Duma made an amazing discovery: chlorine is able to replace hydrogen in organic compound molecules. For example, in chlorination of acetic acid, one hydrogen of the methyl group is replaced by chlorine, then another, the third ... But the most striking was that, according to the chemical properties, chloroacetic acids differed not much from the acetic acid itself. The discovered Duma class of reactions was completely inexplicable by the electrochemical hypothesis and the theory of the radicals of Berzelius (according to the French Chemist of Loran, the discovery of chloroacetic acid was like a meteor, which destroyed the whole old school). Britzelius, his students and followers rapidly challenged the correctness of the work of Dumas. In the German magazine "AnnaLen Der Chemie und Pharmacie" there was a mockery letter of the famous German chemist Friedrich Völer under the pseudonym S.S.N. Windier (German "Schwindler" means "liar", "deceiver"). It reported that the author was replaced into the fiber (C 6 H 10 O 5) and all carbon atoms. hydrogen and oxygen on chlorine, and the properties of the fiber did not change. And that now in London make warm muscles from a wool consisting of ... from pure chlorine.

Chlorine and water

Chlorine significantly dissolves in water. At 20 ° C in one volume of water, 2.3 chlorine volume dissolves. The aqueous solutions of chlorine (chlorine water) - yellow. But over time, especially when stored in light, they are gradually discolored. This is explained by the fact that the dissolved chlorine partially interacts with water, hydrochloric acids are formed: Cl 2 + H 2 O → HCl + HOCl. The last unstable and gradually decomposes on HCl and oxygen. Therefore, the chlorine solution in water gradually turns into a solution of hydrochloric acid.

But at low temperatures, chlorine and water form a crystallide of an unusual composition - CL 2 · 5 3/4 H 2 O. These greenish-yellow crystals (stable only at temperatures below 10 ° C) can be obtained, flowing chlorine through ice water. The unusual formula is explained by the structure of the crystallohydrate, and it is determined primarily by the structure of the ice. In the crystal lattice of ice, the H 2 molecule can be located in such a way that there are naturally spaced emptiness between them. Elementary cubic cell contains 46 water molecules, between which there are eight microscopic voids. In these voids, chlorine molecules are settled. The accurate formula of chlorine crystalline is therefore must be recorded as follows: 8cl 2 · 46N 2 O.

Poisoning chlorom

The presence in the air is already about 0.0001% chlorine affecting the mucous membranes. Permanent stay in such an atmosphere can lead to a disease of the bronchi, dramatically impairs appetite, gives a greenish tone of the skin. If the chlorine content in the air is 0.1 ° / o, then acute poisoning may occur, the first sign of which is the attacks of the strongest cough. In case of poisoning, the chlorine requires absolute peace; It is useful to inhale oxygen, or ammonia (scent ammonia alcohol), or a pair of alcohol with ether. According to the existing sanitary standards, the chlorine content in the air of industrial premises should not exceed 0.001 mg / l, i.e. 0.00003%.

Not only poison

"That wolves are greedy, everyone knows." That chlorine poisonous is also. However, in small doses, poisonous chlorine can sometimes serve as an antidote. Thus, victims of the hydrogen sulfide give sniff unstable chlorine lime. Interacting, two poison is mutually neutralized.

Analysis on chlorine

To determine the chlorine content, the air sample is passed through absorbers with acidified solution of potassium iodide. (Chlorine displaces iodine, the number of last is easily determined by titration using a solution Na 2 S 2 O 3). To determine the chlorine microcolism in the air, a colorimetric method is often used, based on a sharp change in the color of some compounds (benzidine, orthotoloidine, methylovine) during the oxidation of them with chlorine. For example, a colorless acidified solution of benzidine acquires yellow color, and neutral - blue. The intensity of the color is proportional to the amount of chlorine.

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Currently, the "gold standard" anodes for chlorine production are considered to be anodes from titanium dioxide, modified by hydroxide oxides, primarily the RUO 2 ruthenium dioxide. Oxide ruthenium-titanium anodes (orta) in English-language literature are known as MMO (Mixed Metal Oxide) or DSA (Dimensionally Stable Anode). A film of alloyed titanium dioxide is obtained directly on the surface of the base of the metal titanium. Despite the high cost, Orta has undeniable advantages compared to graphite anodes:

Several times a large permissible current density allows to reduce the size of the equipment;
- there are practically no corrosion products of the anode, which sharply simplifies the cleaning of the electrolyte;
- Anodes have excellent corrosion resistance, capable of working in industrial conditions for more than a year without replacement (repair).

For the manufacture of the anodes of the chlorine production of perspectives and other materials. However, this is the topic of a separate (and large) publication (- approx. Ed.).

Due to the toxicity and high cost of mercury, the third version of the electrolyzers is actively developing - membrane, currently being main in developed countries. In this embodiment, the cathode and anodic space is separated by an ionon-exchange membrane, permeable for sodium ions, but not transmitting anion. At the same time, as in the mercury process, pollution of alkaline Catholyte chloride is excluded.

The material for the manufacture of chlorine production membranes is nafion (NAFION) - ionomer based on polytetrafluoroethylene with adhesive groups of perfluorvinyl sulfonic ether. This material developed in the 60s of the last century by DuPont is characterized by excellent chemical, thermal and mechanical resistance and satisfactory conductivity. To date, it remains the material of the choice when building a plurality of electrochemical installations (- approx. Ed.).

No matter how negatively related to public restrooms, nature dictates their rules, and they have to visit them. In addition to the natural (for this place) odors, another familiar fragrance is a chlorine used for disinfection of the room. It received its name due to the main acting substance in it - Cl. Let us learn about this chemical element and its properties, as well as give a chlorine characteristic under the position in the periodic system.

How this element was opened

For the first time, the chlorine-containing compound (HCl) was synthesized in 1772 by the British priest Joseph attracted.

After 2 years, his Swedish colleague Karl Shelele managed to describe the method of isolating CL by means of a reaction between hydrochloric acid and manganese dioxide. However, this chemist did not understand that a new chemical element is synthesized as a result.

For almost 40 years, it took a scientist to learn how to produce chlorine in practice. For the first time, this was done by the British Gemphri Davy in 1811. At the same time, he used another reaction, rather than its theoretical predecessors. Davy with the help of electrolysis decomposed on the components of NaCl (known to the majority as a kitchen salt).

After having studied the resulting substance, the British chemist realized that it was elementary. After that, Davy's discovery not only called him - Chlorine (chlorine), but was able to give a characteristic chlorine, though she was very primitive.

Chlorin turned into chlorine (Chlore) thanks to Joseph Gay-Loussaka and in this form exists in French, German, Russian, Belarusian, Ukrainian, Czech, Bulgarian and some other languages \u200b\u200btoday. In English to this day, the name "Chlorin" is used, and in the Italian and Spanish "Chloro".

In more detail, the element in question was described by Jens Burtsellius in 1826. It was he who was able to determine its atomic mass.

What is chlorine (CL)

Having considered the opening history of this chemical element, it is worth learn about it in more detail.

The name chlorine was formed from the Greek word χλωρός ("green"). It was given because of the yellowish-greenish color of this substance

Independently chlorine exists like Di-Toman gas CL 2, but in this form in nature it is practically not found. It appears more often in various connections.

In addition to the distinctive shade, the chlorine is characterized by a sweet-caustic smell. It is a very poisonous substance, so when entering the air and inhalation, man or animal is capable of leading to their death (depends on the concentration CL).

Since chlorine is heavier than air almost 2.5 times, it will always be below him, that is, the earth itself. For this reason, with suspected CL, it should be climbed as high as possible, since there will be a smaller concentration of this gas.

Also, in contrast to some other poisonous substances, chlorine-containing has a characteristic color, which can afford to visually identify them and take action. Most standard gas masks help protect the respiratory and mucous membranes from defeating CL. However, for complete safety, more serious measures should be taken, up to the neutralization of a poisonous substance.

It should be noted that it is from the use of chlorine as a poisonous gas in 1915. Beginning of its history, chemical weapons. As a result of the use of almost 200 tons of matter, 15 thousand people were poisoned in a few minutes. A third of them died almost instantly, the third received permanent damage, and only 5 thousand managed to escape.

Why is such a dangerous substance still not prohibited and is produced annually by millions of tons? It's all about its special properties, and to understand them, it is worth considering the characteristic chlorine. The easiest way to do is using the Mendeleev table.

Chlorine Characteristic in the Periodic System

Chlorine like halogen

In addition to the extreme toxicity and caustic odor (characteristic of all representatives of this group) Cl is greatly soluble in water. Practical confirmation of this is the addition of chlorine-containing detergents into the water for the pools.

When contacting with wet air, the substance under consideration begins to smoke.

Properties Cl as Nemmetalla

Considering the chemical characteristics of chlorine, it is worth paying attention to its non-metallic properties.

It has the ability to form compounds with almost all metals and non-metals. As an example, you can bring a reaction with iron atoms: 2fe + 3Cl 2 → 2FeCl 3.

Often, catalysts must be used for reactions. In this role, H 2 O.

Often, the reaction with the CL is endothermic character (absorb heat).

It is worth noting that in crystalline form (in the form of powder) chlorine interacts with metals only when heated to high temperatures.

Responding to other non-metals (except for 2, n, f, with and inert gases), CL forms compounds - chlorides.

With the reaction C O 2, extremely unstable and inclined to decay oxide are formed. In them, the degree of oxidation CL is able to manifest itself from +1 to +7.

When interacting with F, fluorides are formed. The degree of oxidation may be different.

Chlorine: characteristics of the substance in terms of its physical properties

In addition to chemical properties, the element in question has and physical.

Effect of temperature on aggregate CL state

Having considered the physical characteristics of the chlorine element, we understand that it is able to move into different aggregate states. It all depends on the temperature regime.

In the normal state, Cl is a gas with high corrosion properties. However, it can easily live. This affects the temperature and pressure. For example, if it is equal to 8 atmospheres, and the temperature is +20 degrees Celsius, CL 2 is an acid-yellow liquid. This aggregate state is capable of preserving up to +143 degrees if the pressure also continues to rise.

When it reaches -32 ° C, the chlorine state ceases to depend on the pressure, and it continues to remain liquid.

Crystallization of the substance (solid state) occurs at -101 degree.

Where in nature there is cl

Having considered the overall characteristic of chlorine, it is worth learn where in nature there may be such a difficult element.

Because of its high reaction activity, it is almost never found in its pure form (therefore, at the beginning of the study, scientists of this element needed years to learn how to synthesize it). Usually Cl is as part of compounds in various minerals: Galite, Silvin, Cainit, Bishofit, etc.

Most of all it is contained in salts mined from marine or oceanic water.

Influence on the body

When considering the characteristics of Chlorine, it was already said more than once that he is extremely poisonous. In this case, the atoms of the substance are contained not only in minerals, but also in almost all organisms, ranging from plants to humans.

Because of the special properties of the CL ions, the cells are better penetrated through the cell membranes (therefore, more than 80% of the total chlorine in the human body is in the intercellular space).

Together with K, Cl is responsible for the regulation of the water-salt balance and as a result - for osmotic equality.

Despite such an important role in the body, in pure form Cl 2 kills all living things - from cells to whole organisms. However, in controlled doses and with short-term exposure, he does not have time to cause damage.

A vivid example of the latest statement is any pool. As you know, water in such institutions are disinfected using CL. At the same time, if a person rarely visits such a institution (once a week or a month) - it is unlikely that it will suffer from the presence of this substance in water. However, employees of such institutions, especially those who are almost all day in water (rescuers, instructors) often suffer from skin diseases or have a weakened immunity.

In connection with all this, after visiting the pools, it is necessary to take a shower - to wash away the possible remnants of chlorine from the skin and hair.

Using Cl human

Remembering the characteristic of chlorine, that it is a "capricious" element (when it comes to interaction with other substances), it will be interesting to know that in the industry it is very often used.

First of all, it is disinfected by many substances.

CL also used in the manufacture of certain types of pesticides, which helps to save the crop of pests.

The ability of this substance to interact with almost all elements of the Mendeleev table (chlorine characteristic as non-metal) helps to produce some types of metals (TI, TA and NB), as well as lime and hydrochloric acid.

In addition to the above CL, it is used in the production of industrial substances (polyvinyl chloride) and medical preparations (chlorhexidine).

It is worth mentioning that today has a more efficient and safe disinfectant - ozone (about 3). However, its production is more expensive than chlorine, and this gas is even more unstable than chlorine (brief description of physical properties in 6-7 p.). Therefore, use ozonation instead of chlorination can still afford a few.

How chlorine is mined

Today there are quite a few ways to synthesize this substance. All of them are divided into two categories:

• Chemical.
• Electrochemical.

In the first case, CL is obtained due to a chemical reaction. However, in practice, they are very expensive and low-performance.

Therefore, the industry prefers electrochemical methods (electrolysis). Three of them: a diaphragm, membrane and mercury electrolysis.

Chlorine (lat. Chlorum), Cl, chemical element VII group of periodic Mendeleev system, atomic number 17, atomic weight 35,453; refers to the family of halogens. Under normal conditions (0 ° C, 0.1 MN / m 2, or 1 kgf / cm 2) yellow-green gas with a sharp annoying smell. Natural chlorine consists of two stable isotopes: 35 CL (75.77%) and 37 Cl (24.23%). Radioactive isotopes with mass numbers 31-47 are artificially obtained, in particular: 32, 33, 34, 36, 38, 39, 40 with periods of a half-life (T ½), respectively, 0.31; 2.5; 1.56 seconds; 3.1 · 10 5 years; 37.3, 55.5 and 1.4 min. 36 Cl and 38 Cl are used as isotopic indicators.

Historical reference. Chlorine was obtained for the first time in 1774 by K. Shelele with the interaction of hydrochloric acid with MNO pyrolymp. However, only in 1810 Davy found that Chlorine is an element and called him Chlorine (from Greek. Chloros is yellow-green). In 1813, J. L. Gay-Loussak offered a chlorine name for this element.

The spread of chlorine in nature. Chlorine is found in nature only in the form of connections. The average chlorine content in the earth's crust (Clark) 1.7 · 10 -2% by weight, in acidic erupted breeds and other 2.4 · 10 -2, in the main and ultrabastern 5 · 10 -3. Water migration plays the main role in the history of chlorine in the earth's crust. In the form of the CL ion - it is contained in the world ocean (1.93%), underground brine and salt lakes. The number of own minerals (mainly natural chlorides) 97, the main of them Galit NaCl (stone salt). Also large deposits of potassium and magnesium chlorides and mixed chlorides are also known: Sylvin KCL, Sylvinitis (Na, K) Cl, KCL carnitis · MgCl 2 · 6H 2 O, KCL Cainit · MgSO 4 · 3H 2 O, Bishofite MgCl 2 · 6H 2 O . In the history of the Earth, the receipt of the NCL contained in volcanic gases into the tops of the earth's crust was of great importance.

Physical properties chlorine. Chlorine has T KIP -34.05 ° C, T pl -101 ° C. Density of chlorine chlorine under normal conditions 3,214 g / l; saturated vapor at 0 ° C 12.21 g / l; liquid chlorine at a boiling point of 1.557 g / cm 3; Solid chlorine at - 102 ° C 1.9 g / cm 3. Pressure of saturated chlorine vapor at 0 ° C 0.369; at 25 ° C 0.772; at 100 ° C of 3,814 mn / m 2 or, respectively, 3.69; 7.72; 38.14 kgf / cm 2. The heat of melting 90.3 kJ / kg (21.5 kal / g); Heat of evaporation 288 kJ / kg (68.8 kal / g); Gas heat capacity at constant pressure 0.48 kJ / (kg · k). Critical chlorine constants: temperature 144 ° C, pressure 7.72 MN / m 2 (77.2 kgf / cm 2), density 573 g / l, specific volume 1.745 · 10 -3 l / g. Solubility (in g / l) chlorine in partial pressure 0.1 MN / m 2, or 1 kgf / cm 2, in water 14.8 (0 ° C), 5.8 (30 ° C), 2.8 ( 70 ° C); In solution of 300 g / l NaCl 1.42 (30 ° C), 0.64 (70 ° C). Below 9.6 ° C in aqueous solutions, hydrates of chlorine variable composition CL 2 · NN 2 O (where n \u003d 6-8) are formed; These are yellow Cubic Singonia crystals that decompose when increasing the temperature of chlorine and water. Chlorine is well soluble in TiCl 4, SiCl 4, SNCl 4 and some organic solvents (especially in hexane with 6 H 14 and carbon tetrachloride CCL 4). Double chlorine molecule (Cl 2). The degree of thermal dissociation CL 2 + 243CH \u003d 2Cl at 1000 K is 2.07 · 10 -4%, at 2500 to 0.909%.

Chemical properties chlorine. External electronic configuration of the CL 3S 2 atom 2 SP 5. In accordance with this, chlorine in the compounds exhibits the degree of oxidation -1, + 1, +3, +4, +5, +6 and +7. The covalent radius of the atom of 0.99Å, the ion radius of CL - 1.82Å, the affinity of the chlorine atom to the electron is 3.65 eV, the ionization energy is 12.97 eV.

Chemically chlorine is very active, directly connects with almost all metals (with some only in the presence of moisture or when heated) and with non-metals (except carbon, nitrogen, oxygen, inert gases), forming appropriate chlorides, react with many compounds, replaces hydrogen In limit hydrocarbons and joins unsaturated compounds. Chlorine displaces bromine and iodine from their compounds with hydrogen and metals; From chlorine compounds with these elements, it is supplanted with fluorine. Alkali metals in the presence of moisture traces interact with chlorine with ignition, most metals react with dry chlorine only when heated. Steel, as well as some rack metals in the dry chlorine atmosphere in conditions of low temperatures, so they are used for the manufacture of equipment and storages for dry chlorine. Phosphorus flammives in the atmosphere of chlorine, forming PCL 3, and with further chlorination - RSL 5; The chlorine sulfur with heating gives S 2 Cl 2, SCL 2 and other S n cl m. Arsenic, antimony, bismuth, strontium, Tellur interact vigorously with chlorine. A mixture of chlorine with hydrogen is lit with a colorless or yellow-green flame with the formation of hydrogen chloride (this is a chain reaction).

The maximum temperature of the hydrogen-chlorine flame is 2200 ° C. Chlorine mixtures with hydrogen containing from 5.8 to 88.5% H 2 are explosive.

Chlorine with oxygen forms oxides: CL 2 O, CLO 2, CL 2 O 6, CL 2 O 7, CL 2 O 8, as well as hypochlorites (chlorothic acid salts), chlorite, chlorates and perchlorates. All chlorine oxygen compounds form explosive mixtures with easily oxidizing substances. Chlorine oxides of a small resistant and can spontaneously explode, hypochlorites during storage slowly decompose, chlorates and perchlorates can explode under the influence of the initiators.

Chlorine in water is hydrolyzed, forming chlorothy and hydrochloric acid: Cl 2 + H 2 O \u003d NCLO + NCl. In chlorination of aqueous solutions, hypochlorites and chlorides are formed by cold alkali: 2NAOH + CL 2 \u003d NACLO + NaCl + H 2 O, and when heated is chlorates. Calcium hydroxide chlorination is obtained by chlorine lime.

In the interaction of ammonia with chlorine, three chloride nitrogen is formed. In chlorination of organic compounds, chlorine either replaces hydrogen, or is attached to multiple bonds, forming various chlorine-containing organic compounds.

Chlorine forms interground compounds with other halogens. Fluorides CLF, CLF 3, CLF 3 are very reactive; For example, in the clf 3 atmosphere, the glass wool is self-proposal. Known chlorine compounds with oxygen and fluorine - chlorine oxyfluorides: CLO 3 F, CLO 2 F 3, Clof, Clof 3 and Fluoro FCLO 4 perchlorate.

Getting chlorine. Chlorine began to produce in industry in 1785 by the interaction of hydrochloric acid with manganese oxide (II) or pyrolyzit. In 1867, the English Chemist of the Dismica developed a method for producing chlorine by oxidation of HCl air oxygen in the presence of a catalyst. Since the late 19th - early 20th century, chlorine is obtained by electrolysis aqueous solutions of alkali metal chlorides. According to these methods, 90-95% chlorine in the world is produced. Small amounts of chlorine are obtained along the production of magnesium, calcium, sodium and lithium by electrolysis of molten chlorides. Two main methods of electrolysis of aqueous solutions NaCl: 1) are used in the electrolyzers with a solid cathode and a porous filter diaphragm; 2) in electrolyzers with a mercury cathode. On both methods on graphite or oxide titanium-ruthenium anode, chlorine gaseous gas is distinguished. In the first method on the cathode, hydrogen is distinguished and a solution of NaOH and NaCl is formed, from which the commercial caustic soda is released by the subsequent processing. According to the second method on the cathode, the amalgam sodium is formed, when it decomposes with clean water in a separate device, a solution of NaOH, hydrogen and pure mercury, which again goes into production. Both methods are given by 1 tons of chlorine 1,125 tons NaOH.

Electrolysis with a diaphragm requires smaller capital investments for organizing chlorine production, gives a cheaper NaOH. The method with a mercury cathode allows you to get very clean NaOH, but mercury losses contaminate the environment.

The use of chlorine. One of the important industries is the chemical industry is the chlorine industry. The main amounts of chlorine are processed at the place of its production in chlorine-containing compounds. Store and transport chlorine in liquid form in cylinders, barrels, railway tanks or in specially equipped vessels. For industrial countries, the following exemplary consumption of chlorine is characterized: the production of chlorine-containing organic compounds is 60-75%; inorganic compounds containing chlorine, -10-20%; to bleach cellulose and fabrics - 5-15%; On sanitary needs and chlorination of water - 2-6% of the total generation.

Chlorine is also applied to chlorination of some ores in order to extract titanium, niobium, zirconium and other

Chlorine in the body. Chlorine is one of the biogenic elements, a permanent component of plant tissues and animals. The chlorine content in plants (a lot of chlorine in halophytes) - from thousandths of percentage to whole percent, in animals - the tenths and hundredths of the percent. The daily need of an adult in chlorine (2-4 g) is covered by food. With food chlorine, usually comes in excess in the form of sodium chloride and potassium chloride. Especially rich in chlorine bread, meat and dairy products. In the body of animals, chlorine is the main osmotically active substance of blood plasma, lymphs, spinal fluid and some tissues. Plays a role in water-salt exchanging, contributing to keeping water tissues. Regulation of acid-alkaline equilibrium in tissues is carried out alongside other processes by change in chlorine distribution between blood and other tissues. Chlorine is involved in the energy exchange in plants, activating both oxidative phosphorylation and photophosphorylation. Chlorine has a positive effect on the absorption of oxygen roots. Chlorine is necessary for the formation of oxygen in the process of photosynthesis insulated chloroplasts. Most nutrient media for artificial cultivation of plants chlorine is not included. It is possible for the development of plants, very low chlorine concentrations are sufficient.

Chlorine poisoning is possible in the chemical, pulp and paper, textile, pharmaceutical industry and others. Chlorine annoys the mucous membranes of the eyes and respiratory tract. A secondary infection is usually attached to primary inflammatory changes. Acute poisoning is developing almost immediately. When inhalation of medium and low concentrations, the chlorine is noted. Streking and chest pain, dry cough, rapid breathing, turning into the eyes, tear, increase the content of leukocytes in the blood, body temperature, etc. Possible bronchopneumonia, toxic edema, depressive states, seizures . In easy cases, recovery occurs after 3-7 days. As distant consequences are observed by the Qatar of the upper respiratory tract, recurring bronchitis, pneumosclerosis and others; It is possible to activate the pulmonary tuberculosis. With prolonged inhalation of small chlorine concentrations, similar, but slowly developing forms of the disease are observed. Prevention of poisoning: sealing of industries, equipment, efficient ventilation, if necessary, using gas masks. The production of chlorine, chlorine lime and other chlorine-containing compounds relates to production with harmful working conditions.