Module 1A True/False question

[JaesalSoma1E]

I found this question in the first audiovisual focus topic and I was confused about what the answer was even after watching the video. I'd appreciate the help!
Determine whether the following statements are true or false:
a. When chemical equilibrium is reached, the composition of the reaction mixture remains constant.
b. If we make a reaction go faster, we can increase the amount of product at equilibrium.

[Nika Gladkov 1A]

a. When chemical equilibrium is reached, the composition of the reaction mixture remains constant.
I said true for this question because the definition of equilibrium is that the concentration or reactions and products stays unchanged. Since the concentrations are the same, the composition remains the same.
b. If we make a reaction go faster, we can increase the amount of product at equilibrium.
I said false for this because the speed of the reaction does not affect the amount of products or reactants produced--they are just made faster. Therefore, equilibrium would be reached faster, but the amount of product would be the same.

[Jonathan Batac - 2D]

a. Remember that when a system reaches equilibrium, there is a constant, K. This constant is the ratio of products and reactions ([P]/[R] or P(products)/P(reactants)). Since the forward and reverse reactions are the same at equilibrium, there should be no instance in which products increase or decrease or reactants increase or decrease (unless, of course, we change physical parameters such as temperature, pressure, etc), so K should stay the same. The statement is true.
b. Making the forward reaction go faster will, for a brief moment in time, cause an increase in products. However, by speeding the forward reaction, the reverse reaction will match that speed, reverting the products to reactants. There is therefore no net change in products or reactants. The statement is false.

[anikamenon2H]

So part A is true because at equilibrium, the concentrations of reactants and products are constant and therefore the composition of the equilibrium remains constant because concentrations aren't changing. Part B is false increasing the forward reaction rate won't increase the amount of products, it will just allow the reaction to reach equilibrium faster, so the amount remains the same at equilibrium.

Hope this helps!

[Shrey Pawar 2A]

Just wanted to add for b Dr. Lavelle touched on the subject when mentioning catalysts. I believe he stated that the catalyst quickens the rate at which the products are produced, but that does not change the amoung. Hope this helps!

[Akash J 1J]

a. True, the concentration of products does not change once the rxn has reached equilibrium because the rates of the forward and reverse rxns are equal. Hence, no change in conc.

b. False, making a rxn go faster (eg. by a catalyst) does not actually change the amount of product formed (or inversely the amount of reactant formed by the reverse rxn). It only serves to reach the same equilibrium value faster.

[Faith Lee 2L]

a. Although the forward and reverse reactions are simultaneously occurring and reactants are changing into products and products are changing into reactants, these two reactions occur at the same rate. Therefore, the actual concentrations (and ratios/K) will not change.
b. Although substances like catalysts can increase the speed at which a reaction occurs, there is no increase in product amount. A catalyst works by decreasing the activation energy (energy required for a reaction to occur), but does not change the actual concentrations of reactant or product.

[Sara Sandri 2B]

Determine whether the following statements are true or false:
a. When chemical equilibrium is reached, the composition of the reaction mixture remains constant.
The way I approached this one was by asking myself: what happens to the concentration if reactants and products when equilibrium is reached? As professor Lavelle mentioned in lecture, the concentrations stay constant and the composition of a reaction mixture is essentially its concentration of products versus reactants. thus, this statement would be true.
b. If we make a reaction go faster, we can increase the amount of product at equilibrium.
This one trapped me a bit because upon first glance, the statement appears to be true! But what reaction is it speeding up: the forward or the reverse? It doesn't tell us so we can't necessarily say more product will be made because what if the reverse reaction is the one being sped up?
Hope that helped!

[Chloe Shamtob 2H]

For part A I said true because when a chemical equilibrium is reached, the concentration of reactants and products stays the same so therefore the composition remains the same.
For part B, I said false because speeding up the reaction does the affect the amount of concentration of reactants or products. We cannot increase the amount of product at equilibrium. By speeding up the reaction, the equilibrium will be reached faster.