The Student Room Group

Pressure constant

2SO2 + O2 <--> 2 SO3

the amounts of sulphur dioxide and oxygen, the catalyst used and the temperature are unchanged but a flask of smaller volume is used (i.e. higher total pressure)

effect on yield of SO3 : Increases
effect on Kp : None

so...if the amount of SO3 has increased, and therefore the amount of SO2 and O2 at equilibirum is less, the partial pressures will be different (since mole fractions have changed)

Since SO3 is higher and other 2 have decreased then the pressure constant will surely be higher as well?

the correct answer is no effect, i was just wondering why it doesn't increase?
there is an explanation of this here