The enthalpies of neutralization of a weak acid HA & a weak acid HB by `NaOH` are -6900 Cal/equivalent & -2900 Cal/equivalent repsectively. When one equivalent of NaOH is added to a solution containing one equivalent of HB, the enthalpy change was -3900 Calories. In what ratio is the base distribute between HA & HB ?

Answer

`1 : 3`

Explanation

1 gram eq. of `NaOH` reacts with `HA` and `HB`
a gram eq. of `NaOH` reacts with `HA`
b gram eq. of `NaOH` react with `HB`
`a+b=1`
`6900 a+2900 b=3900`
`{:(a=0.25,,a:b),(b=0.75,,1:3):}`