Chemistry

Step 1: Understanding the Concept:
The question asks about the chemical precursor used in the industrial synthesis of chloroform (CHCl ).
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 ).
Step 3: Final Answer:
Methane is the gas used to make chloroform.