The system is originally at equilibrium with [butane] = 1.0 M and [isobutane] = 2.5 M. If 0.50 mol/L of isobutane is suddenly added and the system shifts to a new equilibrium position, what is the equilibrium concentration of butane?

1.14 M

Explanation:

Let's consider the following reaction.

butane ⇄ isobutane

We can use the concentrations at equilibrium to calculate the equilibrium constant.

Kc = [isobutane] / [butane]

Kc = 2.5 / 1.0

Kc = 2.5

If we add 0.50 M of isobutane, we get [isobutane] = 2.5 + 0.50 = 3.0 M.

This will be an initial concentration in an ICE chart.

        butane ⇄ isobutane

I           1.0              3.0

C         +x                -x

E        1.0+x           3.0-x

The equilibrium constant is:

Kc = 2.5 = [isobutane] / [butane]

2.5 = (3.0-x) / (1.0+x)

2.5 + 2.5x = 3.0-x

x = 0.14

The equilibrium concentration of butane is:

[butane] = 1.0+x = 1.14 M

i just calculated it all out, and not including weekends, and all the different days off. as of this school year (2018-2019) students are spending 2198 hours in school this year

it’s previous models   because when i picked that son of a gun’s answer it was wrong look for previous models because they might make it a different letter