Quiz 1 - Chemical Equilibrium | Chemical Equilibrium
General Chemistry 2 - Quiz 1 - Chemical Equilibrium
In the context of Le Châtelier’s Principle, what is the effect of adding more reactant to a system at equilibrium?
According to Le Châtelier’s Principle, if more reactant is added to a system at equilibrium, the system will respond by shifting to the right to favor the forward reaction and partially offset the change, forming more products. This minimizes the disturbance to the equilibrium.
Which option correctly describes the effect of increasing pressure on a gaseous equilibrium that has a higher number of moles of gas on the reactant side?
When pressure is increased on a gaseous equilibrium where the reactant side has more moles of gas, the system will shift towards the side with fewer moles of gas to reduce pressure, which in this case is the right side with the products. This is another application of Le Châtelier’s Principle.
What is the impact of temperature increase on an exothermic equilibrium reaction?
Increasing the temperature of an exothermic equilibrium reaction provides more heat, which according to Le Châtelier’s Principle, causes the system to shift towards the reactants as it favors the endothermic direction to absorb the extra heat and restore equilibrium.
If a catalyst is added to a reaction at equilibrium, how will it affect the equilibrium position and rate of reaction?
Adding a catalyst to a reaction at equilibrium accelerates both the forward and reverse reactions equally. It lowers the activation energy but does not affect the position of equilibrium or the equilibrium constant (K).
What is the effect of a decrease in volume on the position of equilibrium of a reaction with more moles of gas on the product side?
Reducing the volume of a reaction vessel for a gaseous equilibrium will result in an increase in pressure. According to Le Châtelier's Principle, the system will shift toward the side with fewer moles of gas to decrease the pressure, which in this case, is the reactant side.
Consider a reaction in equilibrium. What effect will adding an inert gas at constant volume have on the partial pressures of the reactants and products?
Adding an inert gas at constant volume does not change the partial pressures of the reactants and products in a mixture of gases because the total number of moles of reactants plus products remains the same.
Which change would most likely favor the formation of more products in the reaction 2 NO2 (g) ⇌ N2O4 (g), which is endothermic in the forward direction?
For an endothermic reaction such as 2 NO2 (g) ⇌ N2O4 (g), increasing the temperature supplies heat, which is effectively a reactant. According to Le Châtelier’s Principle, this will shift the equilibrium to the right, favoring the formation of more N2O4 (g).
How does the addition of a solvent to a system in equilibrium affect the equilibrium concentration of the solute?
Adding more solvent to a system at equilibrium will dilute the solute, decreasing its concentration. However, the total amount of solute in the system remains constant, since adding solvent does not change the amount of solute present.
Which of the following best defines chemical equilibrium?
Chemical equilibrium is the state in which the forward and reverse reaction rates are equal, and there is no net change in the concentrations of reactants and products, although reactions continue to occur.
Which of the following expressions represents the equilibrium constant Kc for the reaction:
N2 (g) + 3 H2 (g) 2 NH3 (g)?
The equilibrium constant expression is written as the concentration of products raised to the power of their coefficients divided by the concentration of reactants raised to the power of their coefficients.