Answer to Question #258577 in General Chemistry for Loyd

Question

When one mole of nitrogen gas, N2, reacts with one mole of oxygen gas,O2 , two moles of nitric oxide,NO , are formed.In the process ,180.5 kJ of heat are required. D.If 3 moles of nitrogen gas,N2, are made to react with three moles of oxygen gas ,O2, how much heat is required in the process? E.How much heat will be released if two moles of nitric oxide, NO, are broken down into one mole of nitrogen gas, N2, and one mole of oxygen gas, O2?

Answer 1

$N 2 ( g ) + O 2 ( g ) + 180 kJ → 2 NO ( g )$

Now, notice that

1

mole of nitrogen gas must react with

1

mole of oxygen gas and take in

180 kJ

of heat in order to form

2

moles of nitric oxide.

Since the oxygen gas is in excess, the amount of nitrogen as that you have in your sample will determine how much heat should be absorbed in order to get the reaction going and how much nitric oxide will be produced.

Use the molar mass of nitrogen gas to convert the sample to moles

$\frac{13.7 g ⋅ 1 mole N 2}{ 28.0134 g} = 0.48905 moles N 2$

You can now use the fact that every  

1

 mole of nitrogen gas that reacts needs  

180 kJ

 of heat -- remember, oxygen gas is in excess, so it' context.

You can now use the fact that every  

1

 mole of nitrogen gas that reacts needs  

180 kJ

 of heat -- remember, oxygen gas is in excess

$\frac{0.48905 moles N 2 ⋅ 180 kJ}{ 1 mole N 2} = 88 kJ$