A 7.45 g sample of calcium carbonate completely decomposes into calcium oxide (lime)and carbon dioxide gas when heated.If 4.17 g calcium oxide is produced,what mass of carbon dioxide must have been formed?

Question

Quizplus · Accepted Answer

We first need to find the mass of carbon dioxide produced. To do this, we can use the balanced chemical equation for the decomposition of calcium carbonate:

CaCO3 → CaO + CO2

From this equation, we can see that for every 1 mole of CaCO3 that decomposes, 1 mole of CO2 is produced. The molar mass of CaCO3 is 100.09 g/mol, so the number of moles of CaCO3 in the sample is:

7.45 g / 100.09 g/mol = 0.0744 mol

Since 1 mole of CaCO3 produces 1 mole of CO2, the number of moles of CO2 produced is also 0.0744 mol. The molar mass of CO2 is 44.01 g/mol, so the mass of CO2 produced is:

0.0744 mol × 44.01 g/mol = 3.28 g

Therefore, the answer is choice A, 3.28 g of CO2 must have been formed.

A 745 G Sample of Calcium Carbonate Completely Decomposes into Calcium