Question

A mixture of `HCOOH` and `H_(2)C_(2)O_(4)` is heated with conc. `H_(2)SO_(4)`. The gas produced is collected and on treating with `KOH` solution the volume of the gas decreases by `1//6th`. Calculate molar ratio of two acids in original mixure.

Answer 1

`underset(1"mol")(HCOOH) underset("Heat")overset("Conc."H_(2)SO_(4))to underset(1"mol")(CO)+H_(2)O`
`underset(1"mol")(H_(2)C_(2)O_(4)) underset("Heat")overset("Conc."H_(2)SO_(4))to underset(1"mol")(CO)+underset(1"mol")(CO_(2))+H_(2)O`
Let a moles of HCOOH and b moles of `H_(2)C_(2)O_(4)` be present in the original mixture.
`"Moles of CO formed "=a+b`
`"Moles of " CO_(2) " formed "=b`
Total moles of gases=a+b+b=a+2b
`CO_(2)` is absorbed by KOH and the volume reduces by 1/6th.
`"Moles of " =(a+2b)/(6)`
`or b=(a+2b)/(6)`
`or a=4b`
`or (a)/(b)=4`
`or a:b=4:1`