The reaction of rusting iron and the heat produced

[George3]

Homework Statement

4Fe+3O2=2Fe2O3 deltaH=-1.65 x 10^3kJ

If there are 15.7 grams of iron and 7.99 grams of oxygen, how much heat will be produced?

Homework Equations

Since Iron is the limiting reagent do I use that to determine the heat released?

The Attempt at a Solution

15.7gFe x 1molFe/55.9gFe x 1molFe/4molFe x -1.65x10^3kJ/1molFe = -116kJ

 

[Borek]

Looks OK to me, but think about sign. You are not asked about delta H for the reaction, but about amount of the heat released.