Q.Chloroform (trichloromethane) was once used as a surgical anaesthetic. Write the equation for its slow aerial oxidation to a toxic product, name that product, and describe the two storage precautions taken to prevent this reaction.

On prolonged exposure to both air and light, chloroform is slowly oxidised: $2\,\text{CHCl}_3 + \text{O}_2 \xrightarrow{\text{light}} 2\,\text{COCl}_2 + 2\,\text{HCl}$, producing carbonyl chloride, commonly known as phosgene, a highly toxic gas (later notorious as a chemical-warfare agent), along with hydrogen chloride. To prevent this slow oxidation, chloroform is conventionally stored in dark-coloured bottles (to exclude the light needed to drive the reaction), filled completely to exclude trapped air/oxygen, and sealed airtight. As a further safeguard, a small amount (about 1%) of ethanol is added to the bottle; should any phosgene form despite these precautions, the ethanol reacts with it, $\text{COCl}_2 + 2,\text{C}_2\text{H}_5\text{OH} \to (\text{C}2\text{H} …

Give both precautions (limiting light/air exposure AND the ethanol additive) -- either alone is an incomplete answer, since the ethanol spec …

Naming the toxic product as chlorine gas or HCl rather than phosgene (carbonyl chloride), which is the specific, more …