Question

A) The following reaction was carried out in a 2.00 L reaction vessel at 1100 K:

C(s)+H2O(g)⇌CO(g)+H2(g)

If during the course of the reaction, the vessel is found to contain 8.00 mol of C, 14.0 mol of H2O, 3.30 mol of CO, and 6.20 mol of H2, what is the reaction quotient Q?

B) The following reaction was performed in a sealed vessel at 772 ∘C :

H2(g)+I2(g)⇌2HI(g)

Initially, only H2 and I2 were present at concentrations of [H2]=3.10M and  [I2]=2.30M. The equilibrium concentration of I2 is 0.0800 M . What is the equilibrium constant, Kc, for the reaction at this temperature?

Answer 1

1) C(s)+H2O(g)⇌CO(g)+H2(g)

changing moles to oncerntration ---> [H2O] = 14moles/2lit = 7 M , [CO]= 3.30/2 = 1.65 M ,  [H2] = 6.20/2 = 3.10 M

Q (reaction quotient)= 1.65*3.10 / 7 = 0.73

2)   H2(g) + I2(g) ⇌ 2HI(g)

initial concerntration   3.10   2.30 0

change in concerntration 3.02 2.22 0.16

equillibrium concerntration 0.0800M 0.0800 M 0.16 (same amount of equillibrium concerntration H2 and I2)   

Kc= [HI]² / [H₂] [I₂] = [0.16]² / 0.08 * 0.08 = 0.0256/ 0.0064= 4