The equilibrium constant for this reaction is 60.2 at 250 kelvin.

If the initial concentrations of hydrogen and iodine are both 0.250,

what is the equilibrium concentration of HI?

And we're also given the balanced equation H2 plus I2 yields 2HI.

Since this is an equilibrium problem, the first thing I want to do is set up my ice

table that gives me a way to summarize the information that's given and

figure out how I'm going to get to the equilibrium concentration to our product.

So I put in I for initial, C for change and E for equilibrium.

When I look back at the problem I see that my initial concentration

of H2 0.0250 my initial concentration of I2 is also 0.250 and

there's no mention of HI being present initially.

And so I assume that concentration initially is 0.

Now I need to look at the change row and to do that I have to look at two things.

One, the stoichiometry of the balance chemical equation and

I have to determine which side is going to be losing substance and

which side is going to be gaining substance.

Because I start with no HI, the only thing I can do on that side is gain.

So that's going to have to be the gain side.

And what I'm going to see is on the reactive side,

I'm going to lose H2 and I'm going to lose I2.

Then I put this in terms of the balance chemical equation,

and I say well if I lose one M of H2 and I represent that as X,

I will also lose one M of I2 and I will gain 2M of HI.

Now I can take my initial row and my change row, and

add them together to get the equilibrium row,

so I end up with 0.250- x for H2,

0.250- x for I2 and 2x for HI.

Now, I want to set up the Kc expression and so I say that Kc