Question

Assertion (A): Hydrogen gas is liberated when metals like Zn, Al, Pb react with caustic alkalies.

Reason (R): Alkalies are soluble in water.

Options

• Both A and R are true and R is the correct explanation of A.

• Both A and R are true but R is not the correct explanation of A.

• A is true but R is false.

• A is false but R is true.

Answer 1

Both A and R are true but R is not the correct explanation of A.

Explanation:

Zinc, aluminium and lead react with caustic alkalis to form soluble salts and liberate hydrogen, so A is true. Although alkalis are soluble in water, this does not explain the hydrogen-producing reaction; therefore, R is true but not the correct explanation.