Enthalpy of neutralisation of acetic acid by `NaOH` is `-50.6KJ//mol` and the heat of neutralisation of a storng acid with a strong bases is `-55..9KJ//mol` . What is the value of `DeltaH` for the ionisation of `CH_(3)COOH` ?

Options

A. `+ 5.3` kJ/mol
B. `+ 6.2` kJ/mol
C. `+ 8.2` kJ/mol
D. `+ 9.3` kJ/mol

Answer

A

Explanation

`CH_(3) COOH(aq) + NaOH(aq) rarr CH_(3)COONa(aq) + H_(2)O(l) , Delta H= -50.6 kJ`/mol
`CH_(3)COOH (aq) hArr CH_(3)COO^(-) (aq). + H^(+)(aq), Delta H_("ion")`
`CH_(3)COO^(-) (aq) + H^(+) (aq) + NaOH (aq) rarr CH_(3)COONa (aq) + H_(2)O(l), Delta H_("neu") = -55.9` kJ/mol
By Hess. Law: `Delta H= Delta H_("ion") + Delta H_("neu")`
`-50.6= Delta H_("ion") + (-55.9)`
`Delta H_("ion") = +5.3` kJ/mol