When firing 100 g of limestone, 40 g of carbon monoxide 4 was obtained

When firing 100 g of limestone, 40 g of carbon monoxide 4 was obtained, considering that all calcium carbonate decomposed, find its percentage in this limestone sample

1. Let’s compose an equation describing the decomposition of calcium carbonate:

CaCO3 = CaO + CO2 ↑;

2. Calculate the chemical amount of carbon dioxide produced:

n (CO2) = m (CO2): M (CO2);

M (CO2) = 12 + 2 * 16 = 44 g / mol;

n (CO2) = 40: 44 = 0.9091 mol;

3. Determine the amount of calcium carbonate:

n (CaCO3) = n (CO2) = 0.9091 mol;

4. Let’s calculate the mass of carbonate:

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

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

m (CaCO3) = 0.9091 * 100 = 90.91 g;

5. Find the mass fraction of calcium carbonate in limestone:

w (CaCO3) = m (CaCO3): m (limestone) = 90.91: 100 = 0.9091 or 90.91%.

Answer: 90.91%.



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.