The marble containing 5% impurities was treated with an excess of nitric acid solution

The marble containing 5% impurities was treated with an excess of nitric acid solution, and 56 liters were released carbon dioxide. Determine the mass of mineral used.

1. Let’s compose the equation of the reaction proceeding under the action of nitric acid on marble:

CaCO3 + 2HNO3 = Ca (NO3) 2 + H2O + CO2 ↑;

2.Calculate the chemical amount of released carbon dioxide:

n (CO2) = V (CO2): Vm = 56: 22.4 = 2.5 mol;

3. Determine the amount of calcium carbonate:

n (CaCO3) = n (CO2) = 2.5 mol;

4.calculate the mass of carbonate:

m (CaCO3) = n (CaCO3) * M (CaCO3);

M (CaCO3) = 40 + 12 + 3 * 16 = 100 g / mol;

m (CaCO3) = 2.5 * 100 = 250 g;

5. find the mass of marble:

m (marble) = m (CaCO3): (1 – w (impurities) = 250: 0.95 = 263.16 g.

Answer: 263.16 g.