Question

The decomposition of a certain mass of $ CaCO_{3}$ gave $ 11.2\,\,dm^{3}$ of $CO_{2}$ gas at STP. The mass of $ KOH $ required to completely neutralize the gas is

• A. 56 g
• B. 28 g
• C. 42 g
• D. 20 g

Answer 1

Answer: (B)

Weight of $ 11.2\,\,dm^{3}$ of $ CO_{2}$ gas at STP
$=44/2=22\,g $
$\underset{56\, g }{ KOH }+ \underset{44\,g}{CO _{2}} \longrightarrow KHCO _{3}$
$\therefore KOH $ required for complete neutralization of $CO_{2}(44\,g)=56\,g$
$\therefore KOH$ required for neutralization of $22\, g$ of $CO_{2}=\frac{56}{44}\times 22=28\,g $