Question

Consider the following reaction with an equilibrium constant of 5.10 at 527oC. CO(g) + H2O(g) ⇌ H2(g) + CO2(g) If [CO] = 0.150 M, [H2O] = 0.250 M, [H2] = 0.420 M, and [CO2] = 0.370 M, calculate Q. ?

Consider the following reaction: 2SO2(g) + O2(g) ⇌ 2SO3(g)

Which of the following would not result in a shift towards an increase in production of SO3?pick the correct answer?

a)Increase in volume

b)Decrease in volume

c)Increase in the amount of SO2

d)Decrease in the amount of SO3

Answer 1

given K = 5.10 at 527 ^oC.

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

moles             0.150              0.250               0.420          0.370

Q is a reaction quotient which is the relative ratio of products to reactants at a given instant. Using either the initial concentrations or initial activities of all the components of the reaction.

Q =   [H₂][CO₂] / [CO][H₂O]

   =   [0.420][.0370] / [0.150][0.250]

=   4.144

i.e. Q is less than K.

Q<K

this means there are more reactants than products, as a result few of rectants converted into product, making reaction shift towards right.

             2SO2(g) + O2(g) ⇌ 2SO3(g)

if shift towards increase in the production of SO3, then it will increase in the product that mean Q>K .

so to re-establish equilibrium, the reaction will progress to the left, towards the reactants,so

1. increase the amount of SO2
2. Decrease in the amount of SO3
3. Increase in volume       occurs but Decrease in volume never occurs.

so option b)Decrease in volume is correct answer.