# Calculate the mass of copper hydroxide (2), which is formed by the interaction of 200 g of 20%

Calculate the mass of copper hydroxide (2), which is formed by the interaction of 200 g of 20% sodium hydroxide solution and an excess of copper sulfate solution (2). As a result of revacation, sodium sulfate is also formed.

Given:

m (NaOH) = 200 g

w% (NaOH) = 20%

Find:

m (Cu (OH) 2) -?

Solution:

CuSO4 + 2NaOH = Na2SO4 + Cu (OH) 2, – we solve the problem based on the composed reaction equation:

1) Find the mass of alkali in the reacted solution:

m (NaOH) = 200 g * 0.2 = 40 g

2) Find the amount of alkali:

n (NaOH) = m: M = 40 g: 40 g / mol = 1 mol

3) We compose a logical expression:

If 2 mol of NaOH gives 1 mol of Cu (OH) 2,

then 1 mole of NaOH will give x mole of Cu (OH) 2,

then x = 0.5 mol.

4) Find the mass of copper hydroxide precipitated during the reaction:

m (Cu (OH) 2) = n * M = 0.5 mol * 98 g / mol = 49 g.

Answer: m (Cu (OH) 2) = 49 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.