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.

Explanation

`HCOOH underset(Delta)overset(H_(2)SO_(4))rarrH_(2)O+CO`
`H_(2)C_(2)O_(4)underset(Delta)overset(H_(2)SO_(4))rarrH_(2)O+CO+CO_(2)`
Let `a` mole of `HCOOH` and `b` mole of `H_(2)C_(2)O_(4)` are present in original mixture.
`:. {:("Mole of CO formed"=,a,+,b,),(,"from",,"from",),(,HCOOH,,H_(2)C_(2)O_(4),),("Mole of" CO_(2)"formed"=,b,,,),(,"from",,,),(,H_(2)C_(2)O_(4),,,):}`
Total mole of gases `= a + b+b=a+2b`
`because CO_(2)` is absorbed by `KOH` and volume reduces by `(1)/(6)`
`:.` Mole of `CO_(2) = (1)/(6) (a+2b)`
`b = (1)/(6)(a+2b)`
`:. a//b = 4` or `a:b::4:1`