In the manufacture of nitric acid by the oxidation of ammonia, the first product is nitric oxide.?

Question

The nitric oxide is then oxidized to nitrogen dioxide.

2NO + O2 --> 2NO2

Calculate the standard reaction enthalpy for the reaction above (as written) using the following data:
N2 + O2 --> 2NO deltaH = 180.5
N2 + 2O2 --> 2NO2 deltaH = 66.4

All answers in negative:
1. 114.1
2. 520.2
3. 975
4. 690.72
5. 128.2
6. 100.3
7. 252.4

Answer 1

Break the reaction down into steps, add up the steps, and there's your answer.

In this case,

2NO = N2 + O2 DeltaH = - 180.5 (reverse a reaction - reverse the sign of the change)

N2 + 3 O2 = 2NO2 DeltaH = 66.4

Add the reactions, cancel out any molecules that occur on both sides, and you will se the answer.

"All answers in negative" just means there's a minus sign missed out to confuse you. Hope this helps.

Answer 2

First locate the proscribing reactant. what's going to run out first: NH3 or O2. 3.80molNH3 x 5molO2/4molNH3 = 4.75molO2. so that you want 4.seventy 5 moles O2 to react with 3.80 moles NH3. you've 5.15 moles O2, better than sufficient. So NH3 is the proscribing reactant. flow with that. 3.80molNH3 x 4molNO/4molNH3 = 3.80mol NO