The reaction, 2 SO3(g) == 2 SO2(g) + O2(g) is endothermic.
Predict what will happen if the temperature is increased.
A. the pressure decreases
B. more SO3(g) is produced
C. Kc increases
D. Kc decreases
E. none of the above
I chose that Kc will increase. Would you agree?
c probably is the best answer.
Yes, I agree with your choice. If the reaction is endothermic, increasing the temperature will shift the reaction towards the products to counteract the temperature increase. According to Le Chatelier's principle, increasing the temperature favors the endothermic reaction, causing an increase in the amount of products (SO2 and O2) and a decrease in the amount of reactants (SO3). As a result, the equilibrium constant, Kc, which is the ratio of product concentrations to reactant concentrations, will increase. Therefore, C. Kc increases is the correct answer.
To determine the effect of increasing the temperature on the given reaction, we need to consider Le Chatelier's Principle. According to this principle, when a system at equilibrium is subjected to a change, it will shift in a way that opposes the change.
In an endothermic reaction like the one given (2 SO3(g) ⇌ 2 SO2(g) + O2(g)), heat is absorbed as reactants form products. Increasing the temperature will provide additional heat to the system.
Based on Le Chatelier's Principle, when the temperature is increased:
A. The pressure does not change because altering the temperature does not directly affect the pressure of the system.
B. The forward reaction is favored, so more SO3(g) will be produced to consume the extra heat.
C. Kc, the equilibrium constant, is determined by the ratio of products to reactants at equilibrium. As more products are formed in response to the increased temperature, Kc will increase.
D. Kc will not decrease because more products are formed to counterbalance the increase in temperature.
E. Since C is the correct answer, none of the other options are correct.
Therefore, it is correct to state that Kc increases when the temperature is increased in an endothermic reaction.