Question

23.Consider the following equilibrium process at 686°C:

CO₂(g) + H₂(g) ⇌ CO(g) + H₂O(g)

The equilibrium concentrations of the reacting species are [CO] = 0.0580 M, [H₂] = 0.0430 M,

[CO₂] = 0.0900 M,

and [H₂O] = 0.0420 M.

(a) Calculate K_c for the reaction at 686°C.

________

(b) If we add CO₂ to increase its concentration to 0.460 mol / L, what will the concentrations of all the gases be when equilibrium is reestablished?

CO₂:

M

H₂:

M

CO:

M

H₂O:

M

22. The equilibrium constant K_c for the decomposition of phosgene, COCl₂, is 4.63 ×10⁻³ at 527°C:

COCl2(g) ⇆ CO(g) + Cl2(g)

Calculate the equilibrium partial pressure of all the components, starting with pure phosgene

at 0.760 atm.

PCOCl2	=	atm
PCO	=	atm
PCl2	=	atm

The dissociation of molecular iodine into iodine atoms is represented as

I₂(g) ⇌ 2I(g)

At 1000 K, the equilibrium constant K_c for the reaction is 3.80

×

10⁻⁵. Suppose you start with 0.0454 mol of I₂ in a 2.29−L flask at 1000 K. What are the concentrations of the gases at equilibrium?

What is the equilibrium concentration of I₂?



What is the equilibrium concentration of I?

Answer 1

CO₂(g) + H₂(g) ⇌ CO(g) + H₂O(g)

Kc = [CO][H2O]/[CO2][H2]

       = 0.058*0.042/0.09*0.043 = 0.63

            CO₂(g) + H₂(g) ⇌ CO(g) + H₂O(g)

I           0.46      0.043       0.058    0.042

C           -x           -x             +x           +x

E         0.46-x     0.043-x     0.058+ x 0.042+x

    Kc   = [CO][H2O]/[CO2][H2]

    0.63   = (0.058+x)( 0.042+x)/(0.46-x)(0.043-x)

               x = 0.0235

[CO2]   = 0.46-x = 0.46-0.0235 = 0.4365M

[H2]     = 0.043-x = 0.043-0.0235 = 0.0195M

[CO]   = 0.058+ x    = 0.058+0.0235 = 0.0815M

[H2O]   = 0.042+x    = 0.042+0.0235 = 0.0655M