What happens to the following reaction at equilibrium if the pressure is decreased?

2H2(g) + O2(g) 2H2O(g)

A. The equilibrium shifts left because Q > K.
B. The equilibrium shifts right because Q < K.
C. The equilibrium shifts left because Q < K.
D. The equilibrium shifts right because Q > K.

I have already ruled out answer C but I'm not sure which one it is. Can someone help me please?

A for apex

Please explain how you eliminated answer C.

The rule with gases is that an INCREASE in P makes the reaction shift to the side with FEWER mols which means an increase in P and the reaction shifts to the right in this reaction (2 mols on right; 3 mols on left). It follows that a decrease in P makes it shift to the left.
Q = Keq at equilibrium = (H2O^)^2/(H2)^2(O2). Why does it shift to the left? Because H2O is too large and H2 and O2 are too small. Therefore, A or C.

Well, well, well, let's dive into the world of reactions and equilibrium! If the pressure decreases, it means we're creating more space for those gaseous molecules to roam around. And what do molecules love to do? Dance, of course!

Now, imagine a party where two hydrogen molecules (H2) are trying to get close to an oxygen molecule (O2) to form a beautiful water molecule (H2O). At equilibrium, this party is already rocking, with the dance floor packed with H2, O2, and H2O molecules.

When you decrease the pressure, it's just like opening a bigger dance floor, giving those molecules tons of room to disco. Now, what happens to our reaction?

Think, think, think. Would the hydrogen and oxygen molecules be more likely to get together and groove, or would they rather stay on their own, not feeling the dance vibes?

If you said they're more likely to mingle and form more water molecules, you're absolutely right! So, the equilibrium would shift to the right, creating more H2O molecules.

And that means the answer is...drumroll, please...option D. The equilibrium shifts right because Q > K.

Hope that clarifies things, my friend! Keep on dancing!

To determine what happens to the reaction at equilibrium when the pressure is decreased, we need to consider Le Chatelier's principle.

Le Chatelier's principle states that when a system at equilibrium is subjected to a change, the system will adjust in a way that minimizes the effect of the change. In this case, a decrease in pressure is the change being considered.

According to Le Chatelier's principle, when the pressure is decreased, the system will respond by shifting in the direction that produces more gas molecules. In this reaction, there are 4 moles of gas molecules on the left-hand side (2H2) and 2 moles of gas molecules on the right-hand side (2H2O).

Therefore, to increase the number of gas molecules, the equilibrium will shift towards the side with more moles of gas, which is the left-hand side. This means that the equilibrium will shift to the left.

Therefore, the correct answer is A. The equilibrium shifts left because Q > K.

To determine what happens to the given reaction at equilibrium when the pressure is decreased, we need to consider Le Chatelier's principle.

In this reaction, we have two gaseous reactants (H2 and O2) and one gaseous product (H2O). Decreasing the pressure implies reducing the number of gas molecules in the system.

According to Le Chatelier's principle, when the pressure of a system is decreased, the equilibrium will shift in the direction that produces more gas molecules. This is because by reducing the pressure, the system tries to counteract the change and regain equilibrium.

In the given reaction, the only side that has fewer gas molecules is the left side, which has 2 moles of gas (2H2), compared to the right side which has 2 moles of gas (2H2O).

Therefore, to increase the number of gas molecules and counteract the decrease in pressure, the reaction will shift to the side with more gas molecules. In this case, the equilibrium will shift towards the right side, resulting in more products being formed.

Based on this analysis, the correct answer is:
B. The equilibrium shifts right because Q < K.