Question

How much calcium oxide would be made by the thermal decomposition of 25 grams of calcium carbonate?

Answer 1

Answer:

14 grams of calcium oxide would be produced by thermal decomposition of 25 grams of calcium carbonate.

Explanation:

You know:

CaCO₃ → CaO + CO₂

In the first place, by stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction) the following quantities react and are produced:

• CaCO₃: 1 mole
• CaO: 1 mole
• CO₂: 1 mole

Being:

• Ca: 40 g/mole
• C: 12 g/mole
• O: 16 g/mole

the molar mass of the compounds participating in the reaction is:

• CaCO₃: 40 g/mole + 12 g/mole + 3*16 g/mole= 100 g/mole
• CaO: 40 g/mole + 16 g/mole= 56 g/mole
• CO₂: 12 g/mole + 2*16 g/mole=  44 g/mole

Then, by stoichiometry of the reaction, the following mass amounts of the compounds participating in the reaction react and are produced:

• CaCO₃: 1 mole* 100 g/mole= 100 g
• CaO: 1 mole* 56 g/mole= 56 g
• CO₂: 1 mole*  44 g/mole= 44 g

You can then apply the following rule of three: if by stoichiometry of the reaction 100 grams of calcium carbonate CaCO₃ produce 56 grams of calcium oxide CaO, 25 grams of CaCO₃ how much mass of CaO will it produce?

$mass of calcium oxide=\frac{25 grams of CaCO_{3} *56 grams of CaO}{100 grams of CaCO_{3} }$

mass of calcium oxide= 14 grams

14 grams of calcium oxide would be produced by thermal decomposition of 25 grams of calcium carbonate.