Chemistry related question

Question

Which is a proper description of chemical equilibrium?

(A)The frequencies of reactant and of product collisions are identical.

(B)The concentrations of products and reactants are identical.

(C)The velocities of product and reactant molecules are identical.

(D)Reactant molecules are forming products as fast as product molecules are reacting to form reactants.

(E)The numbers of moles of reactants and products are equal.

Could you also explain why you know that’s the correct answer/option?

Answer 1

Hey Armaan,

I see you have a lot of questions posted tonight. I'll answer one, and maybe in the future you'll decide to just do an instant book request for a live tutor - it will save some time and be more helpful.

At chemical equilibrium, the concentrations of products and reactants are not changing. However, the reaction is still happening, both forwards and backwards at the same rate.

a) seems to assume that collision = reaction, which is not the case. A collision only provides the opportunity for a reaction.

b) misunderstands the definition. The concentrations just have to stay the same, they do not need to be equal. It's possible, but I'd say it's extremely rare for this to be true during equilibrium.

c) No. Velocity of particles does affect reaction rates (it's related to temperature), but there are many other factors. Nothing special happens when multiple particles have the same velocities.

d) This is basically the definition - forward and reverse reactions happening at the same rate.

e) This is essentially the same as choice b.