# The marble containing 5% impurities was acted upon with an excess of 10% nitric acid solution, and 5.6 liters

The marble containing 5% impurities was acted upon with an excess of 10% nitric acid solution, and 5.6 liters (under normal conditions) of gas were released. Determine the mass of mineral used. 1) Let’s compose the reaction equation:
СaCO3 + 2HNO3 = Ca (NO3) 2 + CO2 ↑ + H2O
2) Let’s calculate the amount of substance CO2:
n (CO2) = V (CO2) / Vm = 5.6 / 22.4 = 0.25 mol.
3) Determine the mass of the mineral:
According to the reaction equation:
n (CaCO3) = n (CO2) = 0.25 mol
m (СaCO3) = n (СaCO3) ∙ M (СaCO3) = 0.25 ∙ 100 = 25 g.
ω (CaCO3) = 100 – ω (impurities) = 100-5 = 95%
m (mineral) = m (СaCO3) ∙ 100% / ω (СaCO3) = 25 ∙ 100/95 = 26.3 g. Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.