Methanol is broken down in the body during digestion - AQA - GCSE Chemistry - Question 9 - 2018 - Paper 2

In the reaction CO(g) + 2H2(g) ⇆ CH3OH(g), the molar ratio of carbon monoxide to hydrogen is 1:2. Therefore, for 4.0 × 10³ moles of hydrogen, the amount of carbon monoxide required would be:

ext{Moles of CO} = rac{4.0 imes 10^3}{2} = 2.0 imes 10^3 ext{ moles}

If the temperature exceeds 250 °C, the yield of methanol will decrease. This occurs because the forward reaction is exothermic, and increasing the temperature shifts the equilibrium position to favor the endothermic reaction, reducing the amount of methanol produced.

Increasing the pressure in the reaction causes the equilibrium to shift toward the side with fewer moles of gas, which in this case is the product side (methanol). Since the reaction has 1 mole of CO and 2 moles of H2 producing 1 mole of CH3OH, higher pressure results in a greater yield of methanol.

A catalyst increases the rate of a reaction by providing an alternative pathway for the reaction with a lower activation energy. This allows more reactant particles to have sufficient energy to react, thereby increasing the frequency of successful collisions.

A catalyst is used in this industrial process to lower the activation energy required for the reaction, which allows the reaction to proceed at a lower temperature. This not only reduces energy costs but also makes the process more efficient.

Using a catalyst has no effect on the equilibrium position or the equilibrium yield of methanol. It only speeds up the rate at which equilibrium is reached without changing the amounts of products and reactants at equilibrium.