Question

Given the following reaction, how many liters of H2 gas are needed to form 35.5 grams of NH3?

N2 + 3H2 -> 2NH3

Answer 1

170.4L

Step-by-step explanation:

The reaction equation is given as:

N₂ + 3H₂ → 2NH₃

Mass of NH₃ = 35.5g

Problem:

How many liters of H₂ are needed to produce 35.5g of NH₃

Solution:

To solve this problem, let us find the number of moles of NH₃;

Number of moles =
`(mass)/(molar mass)`

Molar mass of NH₃ = 14 + 3(1) = 17g/mol

So;

Number of moles =
`(35.5)/(17)` = 5.07mole

From the balanced reaction equation:

2 mole of NH₃ will be produced from 3 mole of H₂

5.07mole of NH₃ will produce
`(5.07 x 3)/(2)` = 7.61mole of H₂

At STP;

1 mole of gas will occupy 22.4L

7.61 mole of H₂ will occupy 7.61 x 22.4 = 170.4L