Question

Br2 and Cl2 can react to form BrCl.

a) Write a balanced chemical equation for this reaction

b) Write the equilibrium expression based on the balanced chemical reaction

The value of K for the reaction is 6.90.

c) At equilibrium, if [Br2] = 0.500 M and [BrCl] = 0.250 M, what is [Cl2]?

d) At equilibrium, if [Br2] = 0.750 M and [Cl2] = 0.450 M, what is [BrCl]?

e) Pure BrCl is placed in a flask and allowed to reach equilibrium in the above reaction. At equilibrium, how are [Br2] and [Cl2] related? For example, if [Br2] = 0.100 M, what is [Cl2]?

Thank you!!

Answer 1

we have

Br2 and Cl2 can react to form BrCl.

a) a balanced chemical equation for this reaction is given as :

Br2 + Cl2 <--------------------> 2 BrCl

b) the equilibrium expression based on the balanced chemical reaction is given as :

Keq = [product]/[reactant]

or

Keq = [BrCl]^2 / ([Br2]*[Cl2])

where

Keq = 6.90.

c) At equilibrium, if [Br2] = 0.500 M and [BrCl] = 0.250 M,

then

Keq = [BrCl]^2 / ([Br2]*[Cl2])

gives

6.90 = (0.250)^2 / ( 0.500 M x [Cl2])

or

[Cl2] = 0.018 M

d) At equilibrium, if [Br2] = 0.750 M and [Cl2] = 0.450 M

then

Keq = [BrCl]^2 / ([Br2]*[Cl2])

gives

6.90 = [BrCl]^2 / (0.750 M x 0.450 M )

or

[BrCl] = 1.53 M

e) Pure BrCl is placed in a flask and allowed to reach equilibrium in the above reaction. At equilibrium, both [Br2] and [Cl2] are equal to each other

as

[Br2] = [Cl2] = 0.100 M.