sorry
EDIT : Q4 a(ii)
I'm glad you managed to find the answer, Relina, but for the sake of other's benefit I'll clear it out.
2SO3(g) <----> 2SO2(g)+ O2(g)
Moles at the start of the experiment: 2 (for SO3) 0 (for SO2) 0 (for O2)
Moles at equilibrium:
1.5 (for
SO2 ---> "75% of SO
3", so you have to do 75% of the initial 2moles of SO
3),
O.5 (for
SO3, because 75% has been disassociated; subtract the moles of initial moles of SO3 with the equilibrium moles of SO2) and
0.5 moles of 0
2 (you did notice in the equation there's only one mole of O
2, so it's half of SO
2 in the equilibrium.)
and than you have to find out the partial pressure, I guess y'all know how to do that.
P.S - Sorry for the late reply.