Answer:
- <u><em>The leftover reactant is the nitrogen gas, N₂.</em></u>
Explanation:
As per your description:
<u>1. Square on the left: N₂(g)</u>
- 3 units of two joint circles: this represents 3 molecules of nitrogen gas, N₂(g).
<u>2. Square on the right: H₂(g)</u>
- 3 units of two joint circles: this represents 3 molecules of hydrogen gas, H₂(g).
<u>3. Reaction</u>
If the maximum possible amount of NH₃ is formed during the reaction, you assume that the reaction goes to completion.
The chemical equation that represents the reaction is:
Which must be balanced:
That means that 1 molecule (or 1 mol) of N₂(g) reacts with 3 molecules (or 3 moles ) of H₂(g) to produce 2 molecules (or 2 moles) of NH₃(g).
Since, the squares show that there are 3 molecules of each reactant, the 3 molecules of hydrogen gas will be able to react with 1 molecule of nitrogen gas. When that happens, all the hydrogen gas is consumend and yet two molecules of nitrogen gas will remain unreacted. Hence, the nitrogen gas is the leftover reactant.