Question

The gas which is used to make chloroform is

• A. Cyanogen
• B. Radon
• C. Propane
• D. Methane

Hint:

Remember the names of the first few alkanes: Methane (1 carbon), Ethane (2 carbons), Propane (3 carbons). Chloroform has one carbon atom, which is a strong clue that it's derived from methane.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
The question asks about the chemical precursor used in the industrial synthesis of chloroform (CHCl\(_3\)).
Step 2: Detailed Explanation:
Chloroform is produced industrially by the chlorination of methane. The reaction involves heating a mixture of chlorine and methane gas. This process is a free-radical substitution reaction and produces a mixture of chlorinated methanes (chloromethane, dichloromethane, chloroform, and carbon tetrachloride), which are then separated by distillation. The primary starting gas is Methane (CH\(_4\)).
\[ \text{CH}_4 + \text{Cl}_2 \rightarrow \text{CH}_3\text{Cl} + \text{HCl} \] \[ \text{CH}_3\text{Cl} + \text{Cl}_2 \rightarrow \text{CH}_2\text{Cl}_2 + \text{HCl} \] \[ \text{CH}_2\text{Cl}_2 + \text{Cl}_2 \rightarrow \text{CHCl}_3 \text{ (Chloroform)} + \text{HCl} \] Step 3: Final Answer:
Methane is the gas used to make chloroform.