JEE Main levelSingle correct optionDifficulty 2 of 3ev014
Assertion (A): Classical smog is a reducing smog. Reason (R): It contains sulphur dioxide, which is a reducing agent, along with smoke from burning coal.
ABoth A and R are true and R is the correct explanation of A
BBoth A and R are true but R is not the correct explanation of A
CA is true but R is false
DA is false but R is true
Answer: A
Classical smog consists of smoke, fog and SOX2. Because SOX2 is oxidised easily (S from +4 to +6), the smog has a reducing character. So both statements are true and R explains A.