Q. 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 neutralise the gas is
A) 56 g
B) 28 g
C) 42 g
D) 20 g
Explanation
(b)
Weight of 11.2 $dm^{3}$ of $CO_{2}$ gas at STP=44/2
=22 g
$KOH + CO_{2} \rightarrow KHCO_{3}$
56 g 44 g
Mass of KOH required for complete neutralisation of 22 g
$CO_{2}$ is =$\frac{56}{44} \times 22 = 28$g
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.