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.