Question

Chloroform kept in brown coloured bottles filled up to the neck.

1. What is the reason for this?

2. Few drops of 1% ethyl alcohol is added to chloroform to be kept for long. Give reason.

Answer 1

1. In the presence of sunlight chloroform undergoes oxidation to form carbony chloride or phosgene, a highly poisonous gas.

This reaction can be avoided by storing it in dark bottles, completely filled upto brim. The use of brown bottles cuts o active light radiations and filling upto brim keeps out air. So chloroform is kept in brown bottles.

2. Addition of a little ethanol fixes the toxic COCI₂ as non-poisonous diethyl carbonate.