Question

What happens to the concentration of NO2(g)when the total pressure on the equilibrium reaction
2 Pb(NO3)2(s) <--> 2 PbO(s) + 4NO2(g) + O2(g) is increased (by compression)?
1. increases
2. Unable to determine
3. remains the same
4. decreases

Answer 1

This is what alerted me to my error above. You know how to do this one now.

Answer 2

There are 5 mols on the right and only 2 on the left so the NO2 would decrease, correct?

Answer 3

Yes but your reasoning is faulty. True that there are 4 mols gas on the right but there are no mols gas on the left.