## Problem 11.45

kaitlindaugherty3L
Posts: 21
Joined: Fri Sep 29, 2017 7:07 am
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### Problem 11.45

Can someone explain problem 11.45? I set up an equation to solve for Cl but I can"t seem to get the right answer.

Krupa Prajapati
Posts: 50
Joined: Sat Jul 22, 2017 3:00 am

### Re: Problem 11.45

Hi! I am going to explain how to do part a, which is very similar to the other two parts. First, we must construct the equilibrium reaction equation.

Cl2 (g) <-> 2Cl (g)

Now, since the problem says there is 2.0 mmol of Cl2 and a 2.0L vessel, we can calculate the molarity of the Cl2 gas, which is found to be 0.0010M. Since there is no mention of the concentration of Cl gas, we can assume that initially there is no Cl gas in the vessel. Therefore, we can set up our ICE chart as such.

Cl2 2Cl
I 0.0010 0
C -x +2x
E 0.0010-x 2x

Because the problem tells us to refer to the Table, from there we learn Kc at 1000K = 1.0 X 10^-5.

We then set up solving for X.

1.2 X 10^-7 = (2x)^2/ (0.0010 - x)

We find that x is 5.5 X 10^-6. Therefore, the concentration of Cl2 is 0.0010 M and the concentration of Cl is 2(5.5 X 10^-6) which is 1.1 X 10^-5 M