Calcination is a process that converts lime to calcium oxide. The reaction may be represented as:

${\mathrm{CaCO}}_3\underset{\mathrm{heat}}{\to }\mathrm{CaO}+{\mathrm{CO}}_2$
The process requires approximately $$DeltaH_r=3000 (kj)/(mol)$$.  How much heat energy is required to convert 10kg of lime to calcium oxide?

This problem requires us to convert mass to moles. In order to do that, we need the periodic table which can be found in the FE Reference Handbook. However, we can use the one provided on Wikipedia. 

Find the number of mols of 10 kg of lime (${\mathrm{CaCO}}_3$).  The periodic table tells us that:

1. Calcium (Ca) has an atomic weight of 40g/mol
2. Carbon (C) has an atomic weight of 12g/mol
3. Oxygen (O) has an atomic weight of 16g/mol

Therefore, ${\mathrm{CaCO}}_3$ has an atomic weight of 40 + 12 + 3*16 = 100g/mol.

Next, we calculate how many mols are in 10kg of ${\mathrm{CaCO}}_3$.

$$10kg*(1000g)/(kg)*(1mol)/(100g)=100mol$$

Finally, we can calculate the heat required to convert 10kg of lime to calcium oxide using $$DeltaH_r$$.

$$3000(kj)/(mol)*100mol=300,000kj$$