11. How many moles of carbon dioxide are produced in the reaction between hydrochloric acid and calcium carbonate when 2 moles of HCl are used to start with? 2 \mathrm{HCl}+\mathrm{CaCO}_{3} \rightarrow \mathrm{CaCl}_{2}+\mathrm{CO}_{2}-\mathrm{H}_{2} \mathrm{O}