Which of the following gives a blue precipitate when NaOH solution is added to it's solution?

 Which of the following gives a blue precipitate when NaOH solution is added to it's solution?

A. Cu²+

B. Fe²+

C. Fe³+

D. Pb²+

The correct answer is A. Cu²⁺ ✅

Explanation:
When sodium hydroxide (NaOH) solution is added to a solution containing Cu²⁺ ions, a blue precipitate of copper(II) hydroxide, Cu(OH)₂, is formed.

• Cu²⁺ + 2OH⁻ → Cu(OH)₂ (blue precipitate)

• Fe²⁺ gives a green precipitate (Fe(OH)₂)

• Fe³⁺ gives a brown precipitate (Fe(OH)₃)

• Pb²⁺ gives a white precipitate (Pb(OH)₂)

👉 Final Answer: A. Cu²⁺

PQN: 37