Question

Calculate the volume of $C{O}_2$ evolved at NTP when 20g of $CaC{O}_3$ is heated strongly.

• A. 3.38 L
• B. 4.48
• C. 5.58 L
• D. 6.68 L

Answer 1

The correct option is B

4.48

The question gives weight of reactants and asks the volume of product. So, it is a weight-volume problem. Start by balancing the reaction

$CaC{O}_3$ $\to$ CaO + $C{O}_{2\left(g\right)}$ $\uparrow$

$\therefore$ 1 mole of $CaC{O}_3$ gives 1 mole of $C{O}_2$

From Avogadro's Law, 1 mole of $C{O}_2$ at NTP occupies 22.4L

$\therefore$ 1 mole of $CaC{O}_3$ = 22.4 L of $C{O}_2$
100g = 22.4L of $C{O}_2$

$\therefore$ 20g = 20 $\times$ $\frac{22.4}{100}$ = 4.48 L of $C{O}_2$