Chemistry - Thermochemistry Question with Solution | TestHub

Given:

${\mathrm{H}}_3{\mathrm{PO}}_4(\mathrm{aq})+3\mathrm{NaOH}(\mathrm{aq})\to {\mathrm{Na}}_3{\mathrm{PO}}_4(\mathrm{aq})+3{\mathrm{H}}_2\mathrm{O}(\mathrm{l})$ ; $\Delta H=-152.4kJ/mol$

${\mathrm{H}}^{+}(\mathrm{aq})+{\mathrm{OH}}^{-}(\mathrm{aq})\to {\mathrm{H}}_2\mathrm{O}(\mathrm{l})$ ; $\Delta H=-56.8kJ/mol$

Calculate the total enthalpy of ionisation (${\Delta }_{i}H$ for the loss of all 3 protons) of ${\mathrm{H}}_3{\mathrm{PO}}_4$ in kJ/mol.