Question

The value of Kc for the reaction between water vapor and dichlorine monoxide is 0.0900 at 25°C.

H2​O(g)+Cl2​O(g) 2HOCl(g)

Part 1

Determine the equilibrium concentration of H2O if the starting concentrations of both reactants are 0.003923  M, with [HOCl]o = 0.000 M.

Part 2

Determine the equilibrium concentration of Cl2O.

Part 3

Determine the equilibrium concentration of HOCl.

Answer 1

Let's prepare the ICE table

[H2O] [Cl2O] [HOCl]

initial 0.003923 0.003923 0

change -1x -1x +2x

equilibrium 0.003923-1x 0.003923-1x +2x

Equilibrium constant expression is

Kc = [HOCl]^2/[H2O]*[Cl2O]

0.09 = (2*x)^2/(0.00392-1*x)^2

sqrt(0.09) = (2*x)/(0.00392-1*x)

0.3 = (2*x)/(0.00392-1*x)

0.00118-0.3*x = 2*x

0.00118-2.3*x = 0

x = 0.000512

At equilibrium:

1)

[H2O] = 0.003923-1x

= 0.003923-1* 0.000512

= 0.00341 M

Answer: 0.00341 M

2)

[Cl2O] = 0.003923-1x

= 0.003923-1* 0.000512

= 0.00341 M

Answer: 0.00341 M

3)

[HOCl] = +2x

= +2* 0.000512

= 0.00102 M

Answer: 0.00102 M