Answer:
If more reactants are added to a reaction that is at chemical equilibrium, the equilibrium will temporarily shift to counteract the change and establish a new equilibrium state. This shift occurs according to Le Chatelier's principle, which states that when a system at equilibrium experiences a change in conditions (such as concentration, temperature, or pressure), it will adjust to partially counteract that change.
Specifically, if you add more reactants to a reaction at equilibrium:
1. **Shift of the Equilibrium Position**: The reaction will shift in the direction that reduces the added reactants. This means that the reactants will be consumed to form more products. Conversely, if you were to remove some of the reactants, the equilibrium would shift in the direction of forming more reactants.
2. **Increase in Product Formation**: As the reaction shifts to form more products, the concentration of products will increase, while the concentration of reactants will decrease. This results in an increase in the concentration of the products relative to the reactants.
3. **Restoration of Equilibrium**: The reaction will continue to shift until a new equilibrium is established. At this new equilibrium, the rates of the forward and reverse reactions will once again become equal, and the concentrations of reactants and products will stabilize.
It's important to note that the extent of the shift and the time it takes to reach the new equilibrium depend on several factors, including the reaction kinetics, the concentrations of the reactants and products, and the temperature. Additionally, the shift will occur in a way that opposes the change imposed on the system. This is why Le Chatelier's principle is often summarized as "a system at equilibrium will shift to relieve any stress or disturbance placed upon it."
In summary, adding more reactants to a reaction at chemical equilibrium will cause the equilibrium to shift toward the formation of more products until a new equilibrium is established. This shift helps maintain the balance between reactants and products and keeps the reaction at a stable equilibrium state.