Question

2NaOH + CuSo4 - Na2SO4 + Cu(OH)2. What mass of Cu(OH)2 is formed when 200 grams of NaOH is used?

Answer 1

NaOH is a strong base while CuSO4 is an acidic salt. When their solutions are mixed with each other, a pale blue precipitate of basic copper hydroxide & a solution of neutral salt sodium sulphate will be formed. This is a double displacement as well as precipitation reaction.

Answer 2

From the given balanced chemical equation, for 2 moles of NaOH consumed, we'll get 1 mole of Cu(OH)2.

So, for 2 * (23 + 16 + 1) g of NaOH, we'll get 1 * (63.5 + 2 * (16 + 1)) g of Cu(OH)2.

Simplified, for 80g of NaOH consumed, we'll get 97.5g Cu(OH)2.

Or, 200g NaOH would give (200g/80g) * 97.5g = 243.75g of Cu(OH)2.