2 replies to this topic

[Adam77]

Using bomb calorimetry I was asked to determine the enthalpy of combustion for a substance.

 

I have the equation:

 

ΔH = ΔU + ΔnRT

 

I understand what all the terms mean apart from the T.

 

I know it's temperature, but which temperature:

 

- Temperature of the surroundings before combustion?

 

- Temperature of the surroundings after combustion?

 

- The change in temperature?

 

Thankyou!

[latexman]

It is change in T to keep PV constant, as the equation applies to ideal gas.

[Adam77]

It is change in T to keep PV constant, as the equation applies to ideal gas.

Thanks for your help! That was my initial thought as using change in temperature was giving me a value much closer to the literature value.