what is the difference between heat of formation and enthaply of formation.While solving questions related to these Should the approach be different??

Dear student,

Numerically both have almost the same value.
However there is a slight difference to be exact. The heat of formation actually signifies the amount of heat released when a compound is formed from its constituent elements or atoms. In other words, All those bond energies required to create the attraction sufficient enough so as to form that compound.

Hence heat of formation is used for theoretical chemistry purpose.

Enthalpy of formation is however for experimental chemistry. It signifies change in enthalpy function which is used to report the change in the process or in other words, The difference in energies of the final state with the initial state.

Say for example, heat of formation for a particular reaction is 30kJ. It means this much amount of energy is released for formation of the product.
However for enthalpy, we need to specify the sign, whether the final state has a larger value or smaller value will change the sign of the Enthalpy change. 

The approach is same, if you are writing the difference of energies, then it is called enthalpy of formation and if you are reporting a data as how much energy is released or absorbed then its heat.

Hope this helps,

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