When CaCO3 is heated CaO and CO2 are produced. How many kg of CaO will be produced in the decomposition of 10 kg of CaCO3?

Question

Mass of Mass: Products

Answer 1

This chemical reaction needs to be first written as an equation, and then balanced if it's not already. When balancing equations, you need to ensure that the atoms are equivalent on either side to obey the law of conservation of mass:

for eg, if our chem equation is CaCO3 + heat => CaO + CO2, we must double check that the individual elements are balanced on either side:

CaCO3 => CaO + CO2

Ca: 1 | Ca: 1

C: 1 | C: 1

O: 3 | O: 3

In this case, we have balanced atoms and no further work is needed.

Now, we have to convert the 10 kg to moles for the starting substance / reactant: CaCO3

Check the periodic table: Ca is 40.078 g/mol; C is 12.011 g/mol; and O is 15.999 g/mol

CaCO3 is approx 40 + 12 + (16*3) = 100 g/mol

Now use conversion factors: 1 kg = 1000 g

10 kg CaCO3 *1000g/kg * 1 mol/100g = 100 mol

Now check the molar ratio of CaCO3 (reactant) to CaO (product): it's 1:1, as demonstrated by our balanced molar equation.

Finally, we know our reaction yielded 100 mol of CaO, and must convert this to kg as requested in the prompt. We need to use conversion factors, this time, for CaO:

CaO is approx 56g/mol

100 mol CaO * 56g/mol * 1kg/1000g = 5.6 kg.