# A solution of copper (II) chloride, weighing 160 g and a mass fraction of 20%

A solution of copper (II) chloride, weighing 160 g and a mass fraction of 20%, was mixed with sodium hydroxide. Calculate the mass of the precipitate formed?

As a result of the reaction of copper chloride with alkali, sodium chloride and copper hydroxide are formed in the form of a precipitate.
CuCl2 + 2NaOH = Cu (OH) 2 + 2NaCl.
The mass of the salt in the solution is.
m (CuCl2) = m (solution) • W (CuCl2) / 100% = 160 g • 20% / 100% = 32 g.
The number of moles of copper chloride.
n (CuCl2) = m / Mr = 32 g / 134.5 g / mol = 0.24 mol.
The number of moles of the formed and the initial salt will be equal.
n (CuCl2) = n (Cu (OH) 2) = 0.24 mol.
The mass of copper hydroxide is.
m (Cu (OH) 2) = n • Mr = 0.24 mol • 97.6 g / mol = 23.4 g. One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.