## 7th edition 5I.3

Alyssa Bryan 3F
Posts: 61
Joined: Fri Sep 28, 2018 12:26 am
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### 7th edition 5I.3

"In a gas phase equilibrium mixture of H2, I2, and HI at 500 K, [HI] = 2.21 x 10^-3 mol/L and [I2] = 1.46 x 10^-3 mol/L. Given the value of the equilibrium constant in table 5G.2, calculate the equilibrium molar concentration of H2."
How do you know what the products and reactants are between H2, I2, and HI to write the K expression? Also, there are 3 K values given in the table, so how do you know which one is the right value to use?

Nahelly Alfaro-2C
Posts: 59
Joined: Wed Nov 15, 2017 3:04 am

### Re: 7th edition 5I.3

I believe that the reactants for this problem would be H2 and I2 and the product would be HI. In addition, you can assume H2 is a reactant that is what the problem is asking to find the concentration for and the concentration for I2 has been provided.

Diviya Khullar 1G
Posts: 59
Joined: Fri Sep 28, 2018 12:19 am

### Re: 7th edition 5I.3

Regarding which K value to use because this question id dealing with concentration and is asking for [H2], you will need to use Kc.