Question

What product is obtained when chloroform reacts with oxygen in presence of light?

• A. Phosgene gas
• B. Phosphine gas
• C. Chlorine gas
• D. Hydrogen gas

Answer 1

The Correct Option is A

When chloroform (CHCl₃) reacts with oxygen (O₂) in the presence of light, it undergoes a photochemical reaction resulting in the formation of phosgene gas (COCl₂). Let's understand the process step-by-step:

1. Chloroform is a compound with the formula CHCl₃. When exposed to light, particularly UV light, it is susceptible to reaction due to the presence of its carbon-halogen bonds.
2. Oxygen in the air acts as an oxidizing agent. When chloroform is exposed to oxygen under light conditions, the energy from the light acts as a catalyst for the reaction.
3. The reaction can be simplified into the equation:
   CHCl₃ + O₂ → COCl₂ + 2HCl
4. In this equation, chloroform reacts with oxygen to form phosgene (COCl₂) and hydrogen chloride (HCl) gas.

The product phosgene gas is notably hazardous and was used as a chemical weapon. Therefore, handling chloroform carefully when exposed to light and air is essential to avoid unintentional formation of phosgene.

Reactants	Conditions	Product
CHCl₃ + O₂	Presence of Light	COCl₂ + 2HCl

As given in the options, the correct product of this reaction is phosgene gas.

Answer 2

When chloroform (CHCl₃) reacts with oxygen (O₂) in the presence of light, it undergoes a photochemical reaction to form phosgene (COCl₂), which is a toxic gas.

The chemical equation for the reaction is as follows:

\[ \text{CHCl}_3 + \text{O}_2 \xrightarrow{\text{light}} \text{COCl}_2 + \text{HCl} \]

This reaction is important in industrial chemistry, where phosgene is used as a reagent in the synthesis of various organic compounds.

The correct option is A: Phosgene gas.