Question

The volume of $C{O}_2$ (in litres) liberated at STP when 10 g of 90 % pure limestone is heated completely, is:

• A. 22.4 L
• B. 2.24 L
• C. 20.16 L
• D. 2.016 L

Answer 1

The correct option is D 2.016 L

$CaC{O}_3\to CaO+C{O}_2$
1 mole $CaC{O}_3$ produces 1 mole $C{O}_2$.

We have $\frac{90}{100}\times 10$ = 9 g pure $CaC{O}_3$

Molar mass $CaC{O}_3$ = 100 g/mole

9 g $CaC{O}_3$ = $\frac{9}{100}$ = 0.09 mole $CaC{O}_3$.

This will produce 0.09 mole $C{O}_2$.
At S.T.P, $1$ mole $=22.4$ L
$0.09$ mole $=2.016$ L