7. The protolysis (or neutralization) of hydronium ion by hydroxide ion yields water, as shown below, and has an enthalpy of -55.7 kJ/mol.
H3O+ + OH- → 2H2O
Given that the neutralization of HCN by NaOH may be viewed as the sum of the protolysis of HCN and neutralization of H3O+ with OH-, calculate the enthalpy for deprotonation of HCN in water under standard state conditions. The enthalpy for the overall reaction is -12.1 kJ/mol.
HCN + H2O → H3O+ + CN- deprotonation (or protolysis) of HCN
Is the protolysis of HCN endothermic or exothermic?