Chemistry MCQ Practice

In the atmosphere, nitrogen can undergo a series of reactions to form nitric acid:

 

 N₂ + O₂ → 2NO
 2NO + O₂ → 2NO₂
 4NO₂ + 2H₂O → 4HNO₃

 

How many moles of nitric acid are formed from 0.25 moles of nitrogen?

 

A)  0.25

 

B)  0.50

 

C)  1.00

 

D)  4.00

 

 

Answer: B

 

Simplest approach:

 

Use reacting ratio for each equation one at a time i.e.

 

N₂:NO = 1:2
→ 0.25 mol N₂ gives 0.50 mol NO

 

NO:NO₂ = 2:2
→ 0.50 mol NO gives 0.50 mol NO₂

 

NO₂:HNO₃ = 4:4
→ 0.50 mol NO₂ gives 0.50 mol HNO₃