Question

What will be the volume of $C{O}_2$ at STP (atm) obtained on heating 10 grams of 90% pure limestone?

• A. $22.4\text{L}$
• B. $2.02\text{L}$
• C. $2.24\text{L}$
• D. $20.2\text{L}$

Answer 1

The correct option is B $2.02\text{L}$

$CaC{O}_3\to CaO+C{O}_2$

Amount of pure $CaC{O}_3=10\times 0.90=9\text{g}$

1 mol of $CaC{O}_3$ decomposes to form 1 mol of $C{O}_2$ = $22.4\text{L}$ of $C{O}_2$ gas, i.e.
$100\text{g}$ of $CaC{O}_3$ decomposes to form $22.4\text{L}$ of $C{O}_2$ gas.
$9\text{g}$ of $CaC{O}_3$ produces = $\frac{22.4}{100}\times 9=2.02\text{L}$ of $C{O}_2$ gas