### 8.85 part C

Posted:

**Mon Jan 22, 2018 1:13 pm**N2(g) + O2(g)---> 2NO (g) deltaHÂ°=180.6 KJ

c) bomb calorimeter; 492 J absorbed. Mass of N2 oxidized?

How I did this problem was (492J/1 mol rxn)(1 mol rxn/1 mol N2)(1 mol/28.02g)=17.6g

Obviously this is the wrong answer, but can someone please explain to me why this logic is incorrect?

Also, in the solutions manual it divides the 492 KJ absorbed by the deltaH value given to get moles? Im confused as to why this works, is this the moles of N2 in the rxn? Why wouldn't it be the total moles of the rxn?

Thanks :)

c) bomb calorimeter; 492 J absorbed. Mass of N2 oxidized?

How I did this problem was (492J/1 mol rxn)(1 mol rxn/1 mol N2)(1 mol/28.02g)=17.6g

Obviously this is the wrong answer, but can someone please explain to me why this logic is incorrect?

Also, in the solutions manual it divides the 492 KJ absorbed by the deltaH value given to get moles? Im confused as to why this works, is this the moles of N2 in the rxn? Why wouldn't it be the total moles of the rxn?

Thanks :)