Question

Assertion (A): NH₄OH helps to differentiate between lead and zinc ions.

Reason (R): Leads forms insoluble compound with ammonia while zinc forms soluble salt.

Options

• If both A and R are true, and R is the correct explanation of A.

• If both A and R are true, but R is not the correct explanation of A.

• If A is true, but R is false.

• If both A and R are false.

Answer 1

If both A and R are true, and R is the correct explanation of A.

Explanation:

When ammonium hydroxide (NH₄OH) is added in excess, lead ions form a chalky white precipitate of lead hydroxide that remains insoluble. In contrast, zinc ions form a white precipitate that completely dissolves in excess NH₄OH to produce a soluble complex salt. This clear difference in solubility allows easy distinction between the two metal ions.