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AS level Chemistry Energetics Q

Zain786H

I'm not sure how the answer is just simply 0, is anyone able to help explain this. ty :smile:

Reply 1

EierVonSatan

By definition the standard enthalpy of formation of an element is 0.

Reply 2

Zain786H

Original post by EierVonSatan

By definition the standard enthalpy of formation of an element is 0.

So does that mean any element by itself eg Carbon would have an enthalpy of formation of 0?

Reply 3

username3718068

Original post by Zain786H

I'm not sure how the answer is just simply 0, is anyone able to help explain this. ty :smile:

definition of standard enthalpy change of formation:

"enthalpy change when one mole of the compound is formed from its consituent elements under standard conditions. All products and reactants are in their standard states"

N is N2(g) is in its standard state so the eqn would like this:
N2(g) => N2(g)
hence enthalpy change is 0.