Consider the following reaction. 2Fe2O3 -- 4Fe + 3O2 deltaH = +824.2KJ The formation of 42.0 g of O2 results in? 1) the absorption of 361 kJ of heat. 2) the absorption of 11500 kJ of heat. 3) the absorption of 1080 kJ of heat.

Question

Consider the following reaction. 2Fe2O3 --> 4Fe + 3O2 deltaH = +824.2KJ The formation of 42.0 g of O2 results in? 1) the absorption of 361 kJ of heat. 2) the absorption of 11500 kJ of heat. 3) the absorption of 1080 kJ of heat.

aaronq · Answer

convert the mass of $O_2$ to moles and divide the value you get by the stoichiometric coefficient (for $O_2$) in the reaction - which is 3 here.

Next multiply by $\Delta H$