Here's how it works:

1. Chlorination of methane: The process starts with methane (CH₄) and chlorine gas. Under specific conditions (high temperature, presence of light), chlorine reacts with methane to form chloromethane (CH₃Cl), dichloromethane (CH₂Cl₂), trichloromethane (CHCl₃), and tetrachloromethane (CCl₄).

2. Formation of chloroform: Chloroform (CHCl₃) is one of the products in this reaction.

However, it's important to note that chlorine is not actually an acid. It's a halogen, and the reaction is a halogenation reaction, not an acid-base reaction.

The term "acid" might be used colloquially in this context, but it's not technically correct.