Balanced Equation for Free Radical Chlorination of Propane

Steps:

• Recognize the reaction as free radical substitution where chlorine replaces one hydrogen in propane.
• Write the general form: C₃H₈ + Cl₂ → C₃H₇Cl + HCl, forming propyl chloride.
• Verify atom balance: left side (3C, 8H, 2Cl); right side (3C, 8H, 2Cl).
• Eliminate unbalanced or incorrect product options.

Why B is correct:

• Matches the standard halogenation formula RH + X₂ → RX + HX, where R is the alkyl group, ensuring conservation of atoms.

Why the others are wrong:

• A: Produces H₂ instead of HCl, violating substitution mechanism.
• C: Suggests cleavage into unrelated chlorides, not monochlorination; unbalanced carbons.
• D: Yields methyl chloride from methane, not propane; unbalanced (missing 2C, 3H).

Final answer: B