A mixture of formic acid and oxalic acid is heated with conc `H_2SO_4`. The gas produced is collected and treated with KOH solution, where the volume decreases by `(1)/(6)` The molar ratio of the two acids (formic acid/oxalic acid) in the original is
(a). `4:1`
(b). `1:4`
(c). `2:1`
(d). `1:2`

Explanation

Let x " mol of "HCOOH and y " mol of "`(COOH)_2` be taken
`underset(x)(HCOOH)overset(H_2SO_4)toH_2O+underset(x)(CO)`
`underset(y)((COOH)_2)overset(H_2SO_4)toH_2Ounderset(y)(CO)+underset(y)(CO_2)`
Total " mol of "`CO+CO_2=x+2y`
Total " mol of "`CO_2=y`
According to the question
`(x+2y)xx(1)/(6)=y`
`therefore(x)/(y)=4:1`
`therefore` Alternatively
Mol fraction of `CO_2=(y)/(x+2y)=(1)/(6)`
`therefore(x)/(y)=4:1`