Question

The molecular mass of carbon dioxide is 44 g. The volume of 132 g of carbon dioxide at STP is

• A. 22.4 L
• B. 67.2 L
• C. 105.6 L
• D. 7.47 L

Answer 1

The correct option is B

67.2 L

Mass of carbon dioxide = 132 g
Molar volume at STP (litres) = 22.4 L
Gram molecular mass of carbon dioxide = 44 g
In case of gases at STP,
Number of moles = $\frac{\text{Volume at STP (litres)}}{\text{Molar volume at STP (litres)}}$ .... (i)

Volume at STP (litres) = Number of moles $\times$ Molar volume at STP (litres) ....(ii)

Number of moles = $\frac{\text{Given mass}}{\text{Gram molecular mass}}$ .... (iii)

After inserting the values of mass of carbon dioxide and gram molecular mass of carbon dioxide in equation (iii) is

Number of moles = $\frac{132}{44}$ = 3
Putting the values of number of moles and of molar volume at STP (litres) in equation (ii)

Volume at STP (litres) = 3 $\times$ 22.4 L = 67.2 L