Question

Given the balanced equation representing a reaction: 4nh3 + 5o2 4no + 6h2o what is the minimum number of moles of o2 that are needed to completely react with 16 moles of nh3?

Answer 1

Key Concepts

• Mole ratios
• Limiting reagent
• Balancing chemical equations

Solution

`4NH_3 + 5O_2 \rightarrow 4NO + 6H_2O`

We're given:

• 
  `n(NH_3)=16\hspace{4}mol`
• 
  `n(O_2)=?`

The mole ratio between NH3 and O2 is 4:5, meaning...

`(n(NH_3))/(4)=(n(O_2))/(5)`

Plug in the given moles of NH3 and solve for moles of O2:

`(16)/(4)=(n(O_2))/(5)`

`n(O_2)=20`

Answer

20 moles of O2 are needed to completely react with 16 moles of NH3.