Copper sulphate solution reacts with sodium hydroxide solution

Analytical Chemistry (10)

Copper sulphate solution reacts with sodium hydroxide solution to form a precipitate of copper hydroxide according to the equation:

 2NaOH + CuSO₄ → Na₂SO₄ + Cu(OH)₂ ↓

(i) What mass of copper hydroxide is precipitated by using 200 gm of sodium hydroxide? [H = 1, O = 16, Na = 23, S = 32, Cu = 64]

(ii) What is the colour of the precipitate formed?

Answer

(i) RMW of NaOH = 40, Cu(OH)₂ = 98

∴ 2 x 40 g precipitate = 98 g

∴ 200 g precipitate = (98 × 200)/80 = 245 g

(ii) Pale blue

• Exam Year: 2019