Question

Gases N2 (g) and H2 (g) are added to a previously evacuated container and react at a constant temperature according to the following chemical equation N2 (g) + H2 (g) → NH3 (g)

Answer 1

The minimum number of moles of H₂ (g) that must be added to the container is three times the initial moles of N₂ (g).

Step-by-step explanation:

In the given chemical equation:

[N₂ (g) + 3H₂ (g) rightarrow
`2NH_3 (g)\]`

we can see that one mole of (N₂) reacts with three moles of (H₂) to produce two moles of (NH₃). This implies that the ratio of moles of (N₂) to moles of (H₂) is 1:3. Therefore, to ensure that all the (N₂) is consumed, the minimum number of moles of (H₂) should be three times the initial moles of (N₂).

For example, if we initially have 2 moles of (N₂), we would need 6 moles of (H₂) to react completely:

`\[2 \, moles \, N_2 + 6 \, moles \, H_2 \rightarrow 4 \, moles \, NH_3\]`

This ensures that all the (N₂) is consumed according to the stoichiometry of the reaction.

In conclusion, to find the minimum moles of (H₂), one can use the stoichiometric coefficients in the balanced equation to establish the mole ratio between (N₂) and (H₂). In this case, the ratio is 1:3, meaning three moles of (H₂) for every mole of (N₂) is the minimum required for complete reaction.

Full Question:

What is the minimum number of moles of H₂ (g) that must be added to a container initially evacuated, along with N₂ (g), to ensure that all the N₂ (g) is consumed in the reaction and NH₃ (g) is the only product?