The enthalpy of formtion of H2O (l) is -280.70 kj/mol and enthalpy of neutrlisation of a strong acid and strong base is -56.70 kj/molwhat is the enthalpy of formation of OH-.

Dear student,

Using Hess's Law we can calculate reaction enthalpies for a variety of reactions using tables of known enthalpies

Many experimentally determined enthalpies are listed by the type of process

• D
H for converting various liquids to the gas phase are listed in tables of enthalpies of vaporization
• D
H for melting solids to liquids are listed in tables of enthalpies of fusion
• D
H for for combusting a substance in oxygen are listed in tables of enthalpies of combustion

The enthalpy change associated with the formation of a compound from its constituent elements is called the enthalpy of formation (DH_f )

Conditions which influence enthalpy changes include:

• temperature
• pressure
• state of reactants and products (s, g, l, aq)