Among the given carbonates/bicarbonates, find the value of a × b
${\mathrm{KHCO}}_3,{\mathrm{NaHCO}}_3,{\mathrm{CaCO}}_3,\mathrm{Ca}{\left({\mathrm{HCO}}_3\right)}_2,{\mathrm{K}}_2{\mathrm{CO}}_3,{\mathrm{Li}}_2{\mathrm{CO}}_3,{\mathrm{Na}}_2{\mathrm{CO}}_3\text{ and }\mathrm{Mg}{\left({\mathrm{HCO}}_3\right)}_2$ 

Number of compounds which liberate CO₂ on reaction with HCl = a
Number of compounds that undergo decomposition on heating to give respective carbon dioxide = b

Carbonates or bicarbonates that react with HCl and liberated carbon dioxide are 8, hence value of a is 8.

${\mathrm{KHCO}}_3,{\mathrm{NaHCO}}_3,{\mathrm{CaCO}}_3,\mathrm{Ca}{\left({\mathrm{HCO}}_3\right)}_2,{\mathrm{K}}_2{\mathrm{CO}}_3,{\mathrm{Li}}_2{\mathrm{CO}}_3,{\mathrm{Na}}_2{\mathrm{CO}}_3\text{ and }\mathrm{Mg}{\left({\mathrm{HCO}}_3\right)}_2$

Carbonates or bicarbonates that decomposes on heating and liberated carbon dioxide are 6, hence value of b is 6.

${\mathrm{KHCO}}_3,{\mathrm{NaHCO}}_3,{\mathrm{CaCO}}_3,\mathrm{Ca}{\left({\mathrm{HCO}}_3\right)}_2,{\mathrm{Li}}_2{\mathrm{CO}}_3,\mathrm{Mg}{\left({\mathrm{HCO}}_3\right)}_2$

Therefore, value of a × b is 48.