How much heat is absorbed during production of 159 g of NO by the combination of nitrogen and oxygen?
N2(g)+O2(g)→2NO(g), ΔH = + 43.0 kcal

Question

How much heat is absorbed during production of 159 g of NO by the combination of nitrogen and oxygen? 
N2(g)+O2(g)→2NO(g), ΔH = + 43.0 kcal

sweetburger · Answer

43kcal is the amount of energy needed to be absorbed to produce 2 moles of NO. Divide the 43kcal by 2 to find the amount of energy needed to be absorbed to produce 1 mole of NO. Now take the 159g of NO and convert it to moles. Multiply this value times (43kcal)/2 to produce the amount of energy needed to be absorbed to produce 159g of NO.

*correct me if im wrong. its been a long time since I have worked on these types of problems.