Answer to Question #63509 in General Chemistry for archy

Question

The equilibrium constant for a reaction

text A  +  B ⇔ Y +  Z end text

is Kc = 0.1.

What amount of A (in mol) must be mixed with 4 mol of B to yield, at equilibrium, 1.1 mol of Y in a volume of 1L? - At the beginning there is no amount of Y or Z present. Give your answer to 2 sig. fig. including trailing zeros.

Answer 1

The Initial, Change, Equilibrium (ICE) table can be used to solve this task. The volume is 1 L so the amount of moles is also the molarity. The ICE table gives:
Kc = x 2 /([A]-x){4- x) = 0.1
As x = 1.1
1.1 2 /(A-1.1)(4- 1.1) = 0.1
[A] = 5.27 moles