Question

What volume of $C{O}_2$ (measured at STP) is obtained on heating 10 grams of 90% pure limestone?

• A. $22.4\text{L}$
• B. $2.016\text{L}$
• C. $2.24\text{L}$
• D. $20.16\text{L}$

Answer 1

The correct option is B $2.016\text{L}$

$CaC{O}_3\to CaO+C{O}_2$
As we are given that $CaC{O}_3$ is 90% pure
So, 9 grams of limestone is present in 10 grams of the taken sample.
Number of moles of $CaC{O}_3$
$=\frac{9}{100}\text{mole}$
We know that:
$\text{Moles of}CaC{O}_3=\text{moles of}C{O}_2=0.09\text{mole}$
volume of one mole of gas at STP $=22.4L$
So volume of $C{O}_2$
$=0.09\times 22.4=2.016\text{L}$