The reaction of 19.6 g of copper (II) hydroxide with hydrochloric acid gave 134 g of a solution of copper (II) chloride.

The reaction of 19.6 g of copper (II) hydroxide with hydrochloric acid gave 134 g of a solution of copper (II) chloride. Calculate the mass fraction of salt in the resulting solution.

1) Let’s compose the reaction equation:
Cu (OH) 2 + 2HCl = CuCl2 + 2H2O
2) Calculate the amount of the substance of the reacted copper (II) hydroxide:
n (Cu (OH) 2) = m (Cu (OH) 2) / M (Cu (OH) 2) = 19.6 / 98 = 0.2 mol.
3) Determine the amount of substance, the mass of the formed copper (II) chloride and its mass fraction in the resulting solution:
n (CuCl2) = n (Cu (OH) 2) = 0.2 mol
m (CuCl2) = n (CuCl2) ∙ M (CuCl2) = 0.2 ∙ 135 = 27 g.
ω (CuCl2) = (m (CuCl2) / m (solution)) ∙ 100% = (27/134) ∙ 100 = 20.15%
Answer: 20.15%.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.