How many litres of ${\mathrm{CO}}_2$ at STP will be formed when 100 ml of 0.1M ${\mathrm{H}}_2{\mathrm{SO}}_4$ reacts with excess of ${\mathrm{Na}}_{2}C{O}_3$ ? 

The chemical reaction for the provided question is:

${\mathrm{Na}}_2{\mathrm{CO}}_3+{\mathrm{H}}_2{\mathrm{SO}}_4\to {\mathrm{Na}}_2{\mathrm{SO}}_4+{\mathrm{H}}_2\mathrm{O}+{\mathrm{CO}}_2.$

1 mole of  ${\mathrm{H}}_2{\mathrm{SO}}_4$ will produce 1 mole (22.4 L at STP) of ${\mathrm{CO}}_2$

100 ml (0.1 L) of 0.1 M ${\mathrm{H}}_2{\mathrm{SO}}_4$ corresponds to (0.1×0.1) 0.01 moles

Thus, $(0.1\times 0.1)0.01$ mole of sulfuric acid will produce $0.01$ mole ( $0.224 \mathrm{L}$ at STP) of carbon dioxide.

Therefore, option C is the correct answer.