Chloroform ($$\text{CHCl}_3$$) Oxidation & Storage

$$2\text{CHCl}_3 + \text{O}_2 \xrightarrow{\text{Light}} 2\text{COCl}_2 \ \text{(Phosgene)} + 2\text{HCl}$$

$$\begin{aligned}\text{COCl}_2 + 2\text{C}_2\text{H}_5\text{OH} \to (\text{C}_2\text{H}_5\text{O})_2\text{C=O} \ \text{(Diethyl Carbonate - Harmless)} + 2\text{HCl}\end{aligned}$$

Concept: Chloroform is slowly oxidized by air in the presence of light to produce phosgene ($$\text{COCl}_2$$), an extremely poisonous gas.

• Storage Rule: Stored in closed, dark amber-colored bottles filled completely to the brim to exclude air and light.
• Role of 1% Ethanol: Added as a stabilizer to convert any formed phosgene into non-toxic diethyl carbonate.