Question

A sealed 1.0L flask is filled with 0.500 mols of I_2 and 0.500 mols of Br_2. When the container achieves equilibrium the equilibrium constant is 1.10x10^{-2}. What is the equilibrium concentration of the product, IBr?

Answer 1

[IBr] = 0.049 M.

Step-by-step explanation:

Hello there!

In this case, according to the balanced chemical reaction:

`I_2+Br_2\rightarrow 2IBr`

It is possible to set up the following equilibrium expression:

`K=([IBr]^2)/([I_2][Br_2]) =0.0110`

Whereas the the initial concentrations of both iodine and bromine are 0.50 M; and in terms of
`x` (reaction extent) would be:

`0.0110=((2x)^2)/((0.50-x)^2)`

Which can be solved for
`x` to obtain two possible results:

`x_1=-0.0277M\\\\x_2=0.0245M`

Whereas the correct result is 0.0245 M since negative results does not make any sense. Thus, the concentration of the product turns out:

`[IBr]=2x=2*0.0249M=0.049M`

Regards!