Question

Consider the reaction below.

2NH₃(g) <--> N₂ (g)+3H₂ (g)

What is the most likely effect to the forward reaction if there is an increase in pressure on this reaction?
O The reactant surface area increases.
O The reaction rate decreases.
O The reaction is not affected at all.
O The reaction stops completely.

Answer 1

An increase in pressure on the reaction 2NH3(g) ⇌ N2(g) + 3H2(g) will most likely cause a shift favoring the forward reaction, reducing the total pressure and increasing the reaction rate until a new equilibrium is achieved.

Step-by-step explanation:

Effect of Pressure on Chemical Equilibrium

Considering the reaction 2NH3(g) ⇌ N2(g) + 3H2(g), an increase in pressure would most likely result in a shift favoring the forward reaction. According to Le Chatelier's principle, the system responds to the increased pressure by favoring the reaction that produces fewer gas molecules; in this case, the forward reaction which converts 4 moles of gas (1 mole of N2 and 3 moles of H2) into 2 moles of NH3. This process effectively reduces the total pressure within the system.

Therefore, the assertion that the reaction rate decreases or the reaction stops completely is incorrect, and the notion that the reactant surface area increases is irrelevant in this context. The increase in pressure will most likely lead to a temporary increase in the reaction rate of the forward reaction until a new equilibrium is established with different concentrations of the reactants and products.