An excess of sodium sulfide solution was added to 27 g of a solution with a mass fraction of copper (II) chloride of 10%.

An excess of sodium sulfide solution was added to 27 g of a solution with a mass fraction of copper (II) chloride of 10%. Determine the mass of precipitated sediment

Given:
m = 27 g
w = 10%
Find: m (draft)
Decision:
CuCl2 + Na2S = CuS (sediment) + 2NaCl
M (CuS) = 64 + 32 = 96 g / mol
M (CuCl2) = 64 + 35.5 * 2 = 135 g / mol
w = mw / mr * 100%
mv = 0.1 * 27 = 2.7 g
By proportion, we find the mass of the sediment
2.7 / 135 = x / 96
x = 1.92 g