Consider the equilibrium below. H2S(g) + I2 (s) 2HI(g) + S(s) Kp =1.34x10-5 @60°
ID: 1026933 • Letter: C
Question
Consider the equilibrium below.
H2S(g) + I2 (s) 2HI(g) + S(s) Kp =1.34x10-5 @60°C
P(H2S)initial = 0.010 atm P(HI)initial = 0.00010 atm
What is the algebraic form of Qp for the reaction above? (note: use partial pressures, not concentrations).
What is the numerical value of Qp using the initial values of the partial pressures provided above?
How does Qp compare to Kp? Is it less than, greater than, or equal to Kp ?
Which direction will the reaction proceed to reach equilibrium?
What are the equilibrium partial pressures of the gases involved in the reaction above?
If the volume of the container is increased, how will this shift the equilibrium once it has been established?
What is the value of DG0 for this reaction?
Draw the free energy vs. reaction progress diagram for this reaction.
Explanation / Answer
Part a
algebraic form of Qp = PHI2 /( PH2S)
Part b
numerical value of Qp = (0.00010)2 / (0.010)
= 10^-6
Part C
Kp > Qp
1.34x10^-5 > 10^-6
Kp is greater than Qp
Part d
The reaction shift to the right
Increase PHI and decrease PH2S
PART E
H2S(g) + I2 (s) 2HI(g) + S(s)
I 0.010 0.00010
C - x +2x
E 0.010-x 0.00010+2x
Kp =1.34x10-5 = (0.00010+2x)2 /(0.010-x)
0.000000134 - 0.0000134x = 10^8 + 4x2 + 0.0004x
x = 0.00013181970
Equilibrium partial pressure
PHI = 0.00010+2*0.00013181970 = 0.0003636394
= 0.0003636
PH2S = 0.010-0.00013181970 = 0.0098681803
= 0.009868