Chlorine: Difference between revisions
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===Synthesis=== | ===Synthesis=== | ||
* Thermal decomposition of [[copper (II) chloride]] produces chlorine gas: | * Thermal decomposition of [[copper (II) chloride]] produces chlorine gas: | ||
*: {{#Chem: | *: {{#Chem: 2CuCl2 { = 993°C} 2CuCl + Cl2(g) }} | ||
* Heat [[hydrochloric acid]] and [[manganese dioxide]]. This is Scheel's original method. | * Heat [[hydrochloric acid]] and [[manganese dioxide]]. This is Scheel's original method. | ||
*: {{#Chem: 4HCl + MnO2 { = heat } MnCl2 + 2 H2O + Cl2}} | *: {{#Chem: 4HCl + MnO2 { = heat } MnCl2 + 2 H2O + Cl2}} | ||
| Line 25: | Line 25: | ||
* Combine hydrochloric acid and [[potassium permanganate]], producing [[potassium chloride]], '''manganese chloride''', [[water]], and [[chlorine]] gas. | * Combine hydrochloric acid and [[potassium permanganate]], producing [[potassium chloride]], '''manganese chloride''', [[water]], and [[chlorine]] gas. | ||
*: {{#Chem: 16 HCl + 2 KMnO4 = 2 KCl + 2 MnCl2 + 8 H2O + 5 Cl2}} | *: {{#Chem: 16 HCl + 2 KMnO4 = 2 KCl + 2 MnCl2 + 8 H2O + 5 Cl2}} | ||
==Purification== | ==Purification== | ||
==Testing== | ==Testing== | ||
Revision as of 00:01, 17 December 2019
| Chemical formula | Cl |
|---|---|
| Atomic Number | 17 |
| OTP appearance | yellowish gas |
| Molar Mass(g/mol) | 35.45 |
| Density(g/cc) | 0.0032 |
| Melting Point(°C) | -101.5 |
| Boiling Point(°C) | -34.04 |
| Solubility in water(g/L) | 4-10 |
| Immediate Danger to Life and Health | 10ppm (inh) |
| NFPA 704 |  0
4
0
OX
|
Chlorine is the only element that is also an industrial chemical.
Uses
Primary
- A key halogen material in general chemistry
- Produces bromine and iodine from saturated salt water
Secondary
- Combined with sodium hydroxide it produces bleach, salt, and water. By itself this process is inefficient, but is promoted by electrolysis.
Natural Sources
- Elemental chlorine does not occur naturally
- Chlorine is sourced from three naturally occurring chloride minerals:
- halite (sodium chloride, salt) in salt water and its evaporite deposits
- sylvite (potassium chloride)
- sal ammoniac (ammonium chloride) in volcanic, fumarole, and coal-fire areas.
Hazards
Chlorine (like fluorine and bromine) is very toxic
Production
Synthesis
- Thermal decomposition of copper (II) chloride produces chlorine gas:
- 2 CuCl2{2 CuCl + Cl2(g)993°C}→
- 2 CuCl2
- Heat hydrochloric acid and manganese dioxide. This is Scheel's original method.
- 4 HCl + MnO2{MnCl2 + 2 H2O + Cl2heat}→
- 4 HCl + MnO2
- Combine hydrochloric acid and an alkali hypochlorite
- Ca(OCl)2 + 4 HCl → CaCl2 + 2 Cl2 + 2 H2O
- Combine hydrochloric acid and potassium permanganate, producing potassium chloride, manganese chloride, water, and chlorine gas.
- 16 HCl + 2 KMnO4 → 2 KCl + 2 MnCl2 + 8 H2O + 5 Cl2
Purification
Testing
test strip
- Mix 20ubm water, 0.1ubm starch and 0.5ubm potassium iodide
- soak paper in this solution, wring out/press
- Expose the strip to the chlorine gas
- Strip color change: goes from light beige/tan (starch) to inky (blur/violet/black) on exposure to chlorine gas.
Storage
- Toxic!
- Store in airtight, watertight glass / PTFE vessel
Disposal
- Bubble through double molar solution of sodium, potassium or calcium hydroxide, producing the salt and the hypochlorite. This is exothermic!
- Cl2 + 2 NaOH(aq) → NaCl(aq) + NaOCl(aq) + H2O + heat