Equilibrium

[hannahzarzar]

In a series of reactions, A → B → C → D, it was determined that the equilibrium constant for the second reaction (B → C) is 0.1. You would expect the concentration of C in a living cell to be: (1) equal to B; (2) one tenth of B; (3) less than one tenth; (4)ten times that of B; (5) more than ten times of B. (Circle any correct answer).

In my opinion, the answer would be 3 because there are still more stages that need to bring the reaction to equilibrium. Is that right???

[JackBean]

if is there equilibrium and no other reactions, it should be 2

[jonmoulton]

But this is a living cell, and so it is not at equilibrium [ Jack, you tricky guy -- making a student THINK ]

[JackBean]

well, even in the tube the equilibrium doesn't mean there's no reaction

[hannahzarzar]

The question mentions that there are a series of reactions - A thru D. It mentions that B is 0.1. Doesn't the equation have to total 1 in order to have equilibrium?

[JackBean]

no, only for the particular reactions

[hannahzarzar]

So, how am I to know how to calculate the answer? I'm totally lost on this question.

[JackBean]

the equilibrium constant is calculated as follows: K = [product]/[substrate], thus, if K = 0.1 = [product]/[substrate] -> [substrate] = 10[product]