Question
A system is at equilibrium. If reactants are added to the system, why does the forward reaction rate become faster than the reverse reaction rate
Answers
GPT-4o mini
In a system at equilibrium, the rates of the forward and reverse reactions are equal, which means the concentrations of reactants and products remain constant over time. When additional reactants are added to the system, the concentration of reactants increases.
According to Le Chatelier's principle, when the equilibrium conditions of a system are changed, the system will shift in a direction that counteracts the change. In this case, adding reactants disturbs the balance of concentrations.
As a result of the increased concentration of reactants:
1. The **forward reaction rate** (the rate at which reactants convert to products) increases because the rate of a reaction generally depends on the concentration of the reactants. More reactants lead to more frequent collisions between molecules, thus accelerating the reaction rate.
2. The **reverse reaction rate** (the rate at which products convert back to reactants) does not increase as rapidly because the concentration of products remains unchanged immediately after adding the reactants.
At the moment just after the reactants are added, the forward reaction rate becomes faster than the reverse reaction rate, causing the system to produce more products. Over time, as products accumulate, the rate of the reverse reaction will increase. Eventually, the system will reach a new equilibrium point where the rates of the forward and reverse reactions are again equal, but with a different ratio of reactants to products compared to the original equilibrium.
In summary, the initial increase in the forward reaction rate compared to the reverse reaction rate is due to the immediate change in reactant concentration following the addition of more reactants.
According to Le Chatelier's principle, when the equilibrium conditions of a system are changed, the system will shift in a direction that counteracts the change. In this case, adding reactants disturbs the balance of concentrations.
As a result of the increased concentration of reactants:
1. The **forward reaction rate** (the rate at which reactants convert to products) increases because the rate of a reaction generally depends on the concentration of the reactants. More reactants lead to more frequent collisions between molecules, thus accelerating the reaction rate.
2. The **reverse reaction rate** (the rate at which products convert back to reactants) does not increase as rapidly because the concentration of products remains unchanged immediately after adding the reactants.
At the moment just after the reactants are added, the forward reaction rate becomes faster than the reverse reaction rate, causing the system to produce more products. Over time, as products accumulate, the rate of the reverse reaction will increase. Eventually, the system will reach a new equilibrium point where the rates of the forward and reverse reactions are again equal, but with a different ratio of reactants to products compared to the original equilibrium.
In summary, the initial increase in the forward reaction rate compared to the reverse reaction rate is due to the immediate change in reactant concentration following the addition of more reactants.