Question

What is the theoretical yield of ammonia, in kilograms, that we can synthesize from 5.22 kg of h2 and 31.5 kg of n2?

Answer 1

Given:

Mass of H2 = 5.22 kg = 5220 g

Mass of N2 = 31.5 kg = 31500 g

To determine:

Theoretical yield of NH3

Step-by-step explanation:

The balanced chemical reaction is:

N2 + 3H2 → 2NH3

1 mole of N2 combines with 3 moles of H2 to form 2 moles of NH3

# moles of N2 = 31500 g/ 28 g.mol-1 = 1125 moles

# moles of H2 = 5200 g/ 1 g.mol-1 = 5200 moles

Therefore N2 is the limiting reagent

Based on the stoichiometry:

1 mole of N2 forms 2 moles of NH3

Thus, 1125 moles of N2 will yield : 1125 * 2 = 2250 moles of NH3

Mass of NH3 = 2250 moles * 17 g/mole = 38250 g = 38.3 kg

Ans: Theoretical yield of NH3 = 38.3 kg

Answer 2

Answer : The theoretical yield of ammonia is, 29.58 Kg

Solution : Given,

Mass of
`H_2` = 5.22 Kg = 5220 g

Mass of
`N_2`= 31.5 Kg = 31500 g

Molar mass of
`H_2` = 2 g/mole

Molar mass of
`N_2` = 28 g/mole

Molar mass of
`NH_3` = 17 g/mole

First we have to calculate the moles of
`H_2` and
`N_2` .

Moles of
`H_2`=
`\frac{\text{ given mass of }H_2}{\text{ molar mass of }H_2}= (5220g)/(2g/mole)=2610moles`

Moles of
`N_2` =
`\frac{\text{ given mass of }N_2}{\text{ molar mass of }N_2}= (31500g)/(28g/mole)=1125moles`

Now we have to calculate the limiting and excess reagent.

The balanced chemical reaction will be,

`N_2+3H_2\rightarrow 2NH_3`

From the balanced reaction we conclude that

1 mole of
`N_2` react with 3 moles of
`H_2`

1125 moles of
`N_2` react with
`3* 1125=3375` moles of
`H_2`

That means
`H_2` is a limiting reagent and
`N_2` is an excess reagent.

Now we have to calculate the moles of ammonia.

From the reaction we conclude that,

3 moles of
`H_2` react to give 2 moles of ammonia

2610 moles of
`H_2` react to give
`(2)/(3)* 2610=1740` moles of ammonia

Now we have to calculate the mass of ammonia.

`\text{Mass of }NH_3=\text{Moles of }NH_3* \text{Molar mass of }NH_3`

`\text{Mass of }NH_3=(1740moles)* (17g/mole)=29580g=(29580)/(1000)=29.58Kg`

Therefore, the theoretical yield of ammonia is, 29.58 Kg