Textbook Problem 5G.1

[Katie 3H]

b) An equilibrium reaction is not affected by increasing the concentrations of products. (ANSWER: FALSE)
d)If one starts with higher concentrations of reactants, the equilibrium concentrations of the products will be larger.(ANSWER:TRUE)

For part B, I thought that only a change in temperature can affect K. So why is it false, shouldn't it be true that equilibrium reactions are not affected by increasing concentrations?

As for part D, how does this make sense? How do initial concentrations and equilibrium concentrations relate?

[Sujin Lim 1H]

For part B, it is important to note that the equilibrium concentration DOES affect an equilibrium reaction, because it allows it to shift left to form more reactants until equilibrium is reached again. This is because an increase in product concentration throws the react off equilibrium, so the reaction/system needs to work in order to restore equilibrium, which it does by forming more reactants.

For part D, the answer is true because if you start out with a higher initial concentration of reactants, more products will be formed. Therefore, at equilibrium, there would be a higher concentration of products compared to if you started out with a smaller amount of reactants. Hope this helps!

[Hannah_Pon_1F]

b) The reaction is affected by the concentrations of products (and reactants) causing shifts in the reaction. However, the equilibrium constant is only affected by temperature.

d) If there are more reactants, more products need to be formed in order to reestablish the equilibrium ratio between reactants and products.

[RossLechner3E]

You are correct in part B for noting that k will remain unchanged and only will be changed by temperature, however, that is not to say the reaction is unaffected. It will have to shift left to reach equilibrium again, thus denoting a change. As for part D, we know more products would have to be formed in an equilibrium reaction if we start with a higher concentration of reactants therefore it must be true.

[Katie 3H]

Ohhh so the changes will affect the reaction but not the equilibrium constant. I see, thank you guys!