## 4J.7

$\Delta G^{\circ} = -nFE_{cell}^{\circ}$

Dakota_Campbell_1C
Posts: 51
Joined: Fri Sep 28, 2018 12:15 am

### 4J.7

When calculating the delta H why do we do the delta H products minus reactants oppose to just using the sum of the enthalpies like the questions previously. Like in questions 4J.5 we just use the products delta H when finding Gibbs.

Nicole Elhosni 2I
Posts: 62
Joined: Fri Sep 28, 2018 12:28 am

### Re: 4J.7

The question is asking for the standard enthalpy of the reaction, which is found by the sum of the standard enthalpy of formation of the products - the standard enthalpy of formation of the reactants.

Nicole Elhosni 2I
Posts: 62
Joined: Fri Sep 28, 2018 12:28 am

### Re: 4J.7

And question 4J.5, it was asking for the formation of NH3 for (a), which is given by N2(g) + 3H2 (g) --> 2NH3 (g). You still standard enthalpy of formation of products - standard enthalpy of formation of reactants, but the standard enthalpy of the reactants is 0.