Here it says consider endothermic reaction at equilibrium. So here this chemical reaction is endothermic. It's as predictive, the reaction will shift to the right, left or no shift after each disturbance all right. So for the first one it says we're removing some O₂. If we look at our equation, O₂ is a product. Think about keeping things balanced. You want to maintain your equilibrium status. I've just removed some product from my chemical reaction. I need to make more. So which way would we need to shift in order to produce more product? We'd have to move in the forward direction or to the right.

Next, I'm adding some glucose right here I'm adding some product got to maintain that equilibrium status. I got a shift in order to reestablish it. How do I get rid of the product that I just added? I have to deplete it, so I have to move in the reverse direction. Moving in the reverse direction will cause a decrease in the product because it's going to be converted into some reactant.

Next, volume of container decreased. So remember if your volume decreases, that's equivalent to the pressure increasing. Remember, if volume is decreasing or pressure is increasing, we shift to the side with less moles of gas. So if we look, we have 12 moles of gas total on this reacted side and then we have 6 moles of gas over here on the product side. We're shifting to the side with less moles of gas. So we have to shift to the right.

Finally, xenon gas added to reaction mixture. Here we're not told that it's under constant volume or constant pressure. So we're assuming it's being done under constant volume. Under constant volume, there will be no shift because you have not disrupted your equilibrium status. Again, they'd have to explicitly say under constant pressure for you to take into account that the changes happen and what which way do I need to go?

All right, So just remember, keep reviewing those Le Chatelier Principle rules and you'll be able to answer questions like this that much easier.