Question

the amount of heat involved in the synthesis of 1 mole of a compound from its elements with all substances in their standard states at 25 degrees celcius is called

Answer 1

The standard enthalpy of formation is defined as the change in enthalpy when one mole of a substance in the standard state (1 atm of pressure and temperature of 298.15 K) is formed from its pure elements under the same conditions.

Answer 2

Answer : It is called as standard heat of formation.

Explanation :

Enthalpy of formation : The enthalpy of change when one mole of a pure compound is formed from its elements is called the enthalpy of formation. It is denoted as, $\Delta H_f$.

Standard heat of formation : When the reacting elements and the product formed are all in their standard state at $25^oC$, the enthalpy change accompanying the chemical reaction is called the standard enthalpy of formation or standard heat of formation. It is denoted as, $\Delta H_f^o$.

Hence, it is called as standard heat of formation.