Problem 65a

Given information

Substance 

The relation between , and

Where,

• is the standard energy change of formation.

• is the standard entropy change of formation.

• is the standard enthalpy change of formation.

Step-by-step explanation

The formula for the calculation of the enthalpy change () 

Where,

• is the specific heat at constant pressure.

• is a change in temperature.

• is a number of moles.

The enthalpy changes only when the temperature changes. It does not depend on pressure. Therefore, it will remain the same even if the standard pressure state is redefine.