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As Level Chemistry Enthalpy

Roman hang Limbu

does Q=MCdeltaT only work for solutions?

Reply 1

Dowel

Original post by Roman hang Limbu

does Q=MCdeltaT only work for solutions?

At AS level you will only be asked about solutions but it can work for other states too.
You can't use 4.2 as the value of c for solids or gases though.

Reply 2

Roman hang Limbu

Original post by Dowel

At AS level you will only be asked about solutions but it can work for other states too.
You can't use 4.2 as the value of c for solids or gases though.

Ok thanks! so what exactly apart from the obvious is the difference between normal enthalpy change and enthalpy change of formation/combustion ( i know the difference between formation and combustion).

Reply 3

Dowel

Original post by Roman hang Limbu

enthalpy change is the change in enthalpy of a reaction (your given an equation and some bond energies and are told to work out change in enthalpy.

formation and combustion refer to specific types of reactions, so you would use the formation enthalpies of bonds to work out the change in enthalpy of a formation and combustion enthalpies to work out the change in enthalpy of a combustion.