Question

How much magnesium carbonate must be heated to obtain 60 tonnes of magnesium oxide?

Answer 1

1 mole of MgCO3 on heating gives 1 mole of MgO and 1 mole of CO2
now 60 tonnes of MgO is
$60 \times {10}^{6 } gm \: \div 40 \: gm \: per \: mole$
$15 \times {10}^{5} moles$
Since mole ratio of MgCO3 and MgO is same, 1500000 mole of MgCO3 is required