Question

At 460 degress celcius, the reaction SO2(g)+ NO2(g) ---> NO(g) + SO3 (g) has K= 84.7. All gases are at an initial pressure of 1.25 atm.

a. Calculate the partial pressure of each gas at equlilibrium.

b. Compare the total pressure initially with the total pressure at equilibrium. Would that relation be ture of all gaseous systems?

Answer 1

SO2(g)+ NO2(g) ---> NO(g) + SO3 (g)

t=0 1.25 1.25 1.25 1.25

t=t, (1.25 - x) (1.25 -x) (1.25 + x)   (1.25 + x)

K =  (1.25 + x)^2/( (1.25 - x)^2) = 84.7

Solving this, we get ,

x = 1

Thus partial pressure of

SO2 = NO2 = 1.25 - 1 = 0.25

NO = SO3 1.25 + 1 = 2.25

(b)

The total pressure initially is equal to the total pressure at equilibrium. This relation will be true for all the systems where the total number of gaseous molecules on Left hand side equals that on the right hand side of the reaction.