Difficult equilibrium question

[dnartS]

8.0 mole of O2(g) is mixed with 10.0 moles of SO2(g) in a 2.0L container forming SO3(g). If 3.0 moles/L of SO3(g) remains at equilibrium. 1.0 mol/L of SO2(g) is removed from the equilibrium, calculate the new eq'm [ ]'s.So I make the rice table

3O2(g) + SO2(g) <--> 2SO3(g)
r 3 ... : ... 1 ... : 2
4.0M ... 5.0M ... 0M (shift right)
c -3x ... -3x ... +2x
e 4.0 -3x ... 5.0-3x ... 2xwhat do I do now?

 

[dnartS]

Guise I need help on this homework question please, it's really bothering me and I am stuck.

 

[Borek]

What were the concentrations of all gases before SO₂ was removed? Can you calculate them from the stoichiometry? After they are calculated - can you use them to calculate equilibrium constant?

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