Question

How is pure chloroform stored?

Answer 1

Pure chloroform storage is critical due to its tendency to decompose in the presence of air and light. Here is how pure chloroform is stored:

1. Inert Atmosphere: Pure chloroform is stored in airtight containers to exclude air, especially oxygen, which can react with chloroform.
2. In dark-colored bottles: Since chloroform decomposes under light, it is stored in amber or dark glass bottles to protect it from light.
3. Addition of stabilizers: To prevent decomposition to phosgene (COCl₂), small amounts of stabilizers like ethanol or amylene are added.
4. Cool temperature: It is stored in a cool place to minimize decomposition.
5. Proper labeling: Containers are labeled with hazard information due to chloroform’s toxicity and potential to produce deadly phosgene.

Decomposition reaction: In presence of oxygen and light, chloroform decomposes as:
\[2 \mathrm{CHCl}_3 + \mathrm{O}_2 \xrightarrow{\text{light}} 2 \mathrm{COCl}_2 + 2 \mathrm{HCl}\]

Thus, chloroform must be stored carefully to prevent this hazardous reaction.