Hydrochloric acid was added to a 10% potassium carbonate solution. In this case, a gas with a volume of 11.2 L was released.

Hydrochloric acid was added to a 10% potassium carbonate solution. In this case, a gas with a volume of 11.2 L was released. Determine the mass of the potassium carbonate solution.

Given:

V (gas) = 11.2 l

w% (K2CO3) = 10%

To find:

m (K2CO3) -?

Decision:

K2CO3 + 2HCl = 2KCl + CO2 + H2O, – we solve the problem based on the composed reaction equation:

1) Find the amount of carbon dioxide. released during the reaction:

n (CO2) = V: Vm = 11.2 L: 22.4 L / mol = 0.5 mol

2) We compose a logical expression:

if 1 mol of K2CO3 gives 1 mol of CO2,

then x mol of K2CO3 will give 0.5 mol of CO2,

then x = 0.5 mol.

3) Find the mass of potassium carbonate that has reacted:

m (K2CO3) = n * M = 0.5 mol * 138 g / mol = 69 g.

4) Find the mass of the entire potassium carbonate solution:

m (solution K2CO3) = 69 g: 0.1 = 690 g.

Answer: m (solution K2CO3) = 690 g.