Calculate the enthalpy of ionisation of week acid
`H_(2)A ` `rarr ` 2 `H^(+)` +`A^(2)` in Kcal/mol if enthalpies of neutralisation of HCl and `H_(2)A` by strong base are "14 Kcal/eq and 11Kcal/eq respectively.

Statement-I : The enthalpy of neutralization of the reaction between HCl and NaOH is -13.7 kCal/mol. If the enthalpy of neutralization of oxalic acid (H_(2)C_(2)O_(4)) by a strong base is -25.4 kCal/mol, then the enthalpy change (|Delta_(r)H|) of the process H_(2)C_(2)O_(4) rarr 2H^(+)+C_(2)O_(4)^(2-) is 11.7 kCal/mol. Statement-II : H_(2)C_(2)O_(4) is a weak acid.

The enthalpy of formation of H_(2)O(l) is -280.70 kJ/mol and enthalpy of neutralisation of a strong acid and strong base is -56.70 kJ/mol. What is the enthalpy of formation of OH^(-) ions?

If H_2(g) +I_2(g) rarr 2HI(g), Delta H=12.40 kcal . The enthalpy of formation of HI is