Question

A chemical engineer is studying the following reaction: H2(9)+12(9) 2 HI(g) At the temperature the engineer picks, the equilibrium constant K, for this reaction is 1.9. The engineer charges ("hills") three reaction vessels with hydrogen and iodine, and lets the reaction begin. She then measures the composition of the mixture inside each vessel from time to time. Her first set of measurements are shown in the table below. Predict the changes in the compositions the engineer should expect next time she measures the compositions

Answer 1

A)
Equilibrium Quotient expression is
Qp = p(HI)^2/p(H2)*p(I2)
= (3.9^2)/(3.54^1)*(2.23^1)
=1.9

comparing Q and k
since Q is equal to K
reaction is at equilibrium

Answer:
H2: no change
I2: no change
HI: no change

B)
Equilibrium Quotient expression is
Qp = p(HI)^2/p(H2)*p(I2)
= (5.4^2)/(4.91^1)*(3.09^1)
=1.9

comparing Q and k
since Q is equal to K
reaction is at equilibrium

Answer:
H2: no change
I2: no change
HI: no change

C)
Equilibrium Quotient expression is
Qp = p(HI)^2/p(H2)*p(I2)
= (3.22^2)/(3.88^1)*(2.57^1)
=1.0

comparing Q and k
since Q is lesser than K
reaction will move in forward direction
Answer:
H2: decrease
I2: decrease
HI: increase