When copper sulfate interacts with caustic soda, 9.8 g of sediment is formed

When copper sulfate interacts with caustic soda, 9.8 g of sediment is formed, determine how much alkali was spent on the formation of a sediment?

Let’s find the amount of substance Cu (OH) 2 (sediment).

n = m: M.

M (Cu (OH) 2) = 98 g / mol.

n = 9.8 g: 98 g / mol = 0.1 mol.

Let’s find the quantitative ratios of substances.

CuSO4 + 2NaOH = Cu (OH) 2 + Na2SO4.

For 1 mol of Cu (OH) 2, there are 2 mol of NaOH.

Substances are in quantitative ratios 1: 2.

The amount of NaOH substance is 2 times greater than the amount of substance = Cu (OH) 2.

n (NaOH) = 2n (Cu (OH) 2) = 0.1 × 2 = 0.2 mol.

Let’s find the mass of NaOH.

M (NaOH) = 40 g / mol.

m = n × M.

m = 40 g / mol × 0.2 mol = 8 g.

Answer: 8 g.