Question

`One way to make ammonia is to synthesize it directly from elemental nitrogen and hydrogen (though this isn't that easy). The equation for this reaction would be N2 + 3 H2 → 2 NH3. If you are able to stream in 7.0 g of N2, what would be the minimum amount of H2 in grams that would be required to completely react with this amount of N2?

A. 1.5 g
B. 0.5 g
C. 0.75 g
D. 3.0 g
E. none of the above

Answer 1

The correct answer is option A.

Step-by-step explanation:

`N_2 + 3 H_2\rightarrow 2 NH_3`

Moles of nitrogen gas =
`(7.0 g)/(28 g/mol)=0.25 mol`

According to reaction, 1 mole of nitrogen reacts with 3 moles of hydrogen gas.

Then 0.25 moles of nitrogen gas will react with:

`(3)/(1)* 0.25 mol=0.75 mol` of hydrogen gas.

Mass of 0.75 moles of hydrogen gas = 0.75 mol × 2 g/mol = 1.5 g

1.5 grams of hydrogen that would be required to completely react with this amount of nitrogen.

Answer 2

Answer: A. 1.5 g

Step-by-step explanation:

`N_2+3H_2\rightarrow 2NH_3`

`\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}`

`\text{Number of moles of nitrogen}=(7.0g)/(28g/mol)=0.25 moles`

According to stoichiometry:

1 mole of
`N_2` requires = 3 moles of
`H_2`

Thus 0.25 moles of
`N_2` will require =
`(3)/(1)* 0.25=0.75moles` of
`H_2`

Mass of
`H_2` required =
`moles* {\text {Molar mass}}=0.75mol* 2g/mol=1.5g`

The minimum amount of
`H_2` in grams that would be required to completely react with this amount of
`N_2` is 1.5 grams.