Air sample from an industrial area of Delhi, which is heavily polluted by `CO_(2)`, was collected and analysed. One such sample of 224 L of air measured at STP was passed through a 500 " mL of " 0.1 M KOH solution, where `CO_(2)(g)` was absorbed completely. 50 " mL of " the above solution was then treated with excess of `BaCl_(2)` solution where all the carbonate was precipitated as `BaCO_(4)(s)`. The solution was filtered off and the filtrate required 30 " mL of " 0.1 M HCl solution for neutralisation.
Q. ppm strength of `CO_(2)(g)` volume by volume `(" mL of " CO_(2)` per `10^(6)` L of air) is

Options

A. 224
B. 2240
C. 100
D. 1000

Answer

D

Explanation

`m" Eq of "KOH` (total)`=500xx0.1xx1=50`
m" Eq of "HCl forKOH(50mL)=30xx0.1=3`
`m" Eq of "excess `KOH` in `500mL=(3)/(50)xx500=30`
`m" Eq of "KOH reactged =50-30=20m" Eq of "CO_(2)`
mmoles of `CO_(2)=(20)/(2)=10=10xx10^(-3)mol`
(1 " mol of "`CO_(2)=22.4L` at STP)
ppm of `CO_(2)=([(10xx10^(-3)xx22.4)xxcancel(10^(3))]mLxx10^(6))/(224xxcancel(10^(3))mL)`
`=1000`