4 When nitrogen and hydrogen react to form ammonia, the reaction can reach a dynamic equilibrium - Edexcel - GCSE Chemistry - Question 4 - 2013 - Paper 1

Increasing the pressure in the reaction results in a shift of the equilibrium position towards the side with fewer gas molecules. In the given reaction, we have 1 mole of nitrogen and 3 moles of hydrogen on the reactant side, totaling 4 moles. On the product side, there are 2 moles of ammonia. Therefore, a higher pressure favors the formation of ammonia, increasing the yield.

Lowering the temperature favors the exothermic reaction, which in this case is the formation of ammonia. As this reaction releases heat, a decrease in temperature shifts the equilibrium position to the right, leading to a higher yield of ammonia.

A catalyst is used in industry to increase the rate of the reaction, allowing it to proceed more quickly without affecting the position of equilibrium.

The balanced equation shows that 1 mole of nitrogen reacts with 3 moles of hydrogen. For 1000 dm³ of nitrogen, the required volume of hydrogen is:

$ext{Volume of hydrogen} = 3 imes 1000 ext{ dm}^3 = 3000 ext{ dm}^3$

To calculate the mass of ammonium nitrate (NH₄NO₃) produced from 34 g of ammonia (NH₃):

1. Calculate moles of NH₃: $ext{Moles of } NH₃ = \frac{34 ext{ g}}{14 + (3 \times 1)} = 2 \text{ moles}$

2. According to the reaction, each mole of NH₃ produces 1 mole of NH₄NO₃, therefore:

$ext{Moles of } NH₄NO₃ = 2$

3. Calculate the mass of NH₄NO₃: $\text{Molar mass of } NH₄NO₃ = 14 + (4 \times 1) + 14 + (3 \times 16) = 80 ext{ g/mol}$ Mass produced = $2 \times 80 ext{ g} = 160 ext{ g}$