Question

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 1

(i)

98 g of CU(OH)₂ is precipitated by using 80 g of NaOH 

1 g of CU(OH)₂ is preapitated by using \(\frac{80}{98}\)g of NaOH 

200 g of CU(OH>2 is preapitated by using \(\frac{80}{98}\times200g\) = 163.26 g of NaOH

(ii) Pale blue precipitates