# Derive relationship between deltaH and T1 and T2

1. Dec 2, 2014

### ybhathena

1. The problem statement, all variables and given/known data

Hi I need to know the derivation of the equation HT2 = delta HT1 + delta Cp delta T and I'm really unsure of where to find this. Does anyone know the derivation of this relationship?

C represents the the specific heat of the substance in question.

H represents enthalpy, so HT1 represents at enthalpy at the first time point measured of only one material being measured.

The equations I have learned so far are deltaG = -RTlnK and deltaG = deltaH - TdeltaS

Last edited: Dec 2, 2014
2. Dec 2, 2014

### Staff: Mentor

I think that this applies to the heat of reaction at two different temperatures.

$$\Delta H(T_2)=\Delta H(T_1)+\Delta C_p(T_2-T_1)$$

where ΔH(Tj) is the heat of reaction at temperature Tj and ΔCp is symbolic of the heat capacities of the products minus the heat capacities of the reactants. The derivation of this equation is based on Hess' Law.

Chet