The correct answer to this question could be A + B ↔ AB. When dealing with pressure, you need to count the number of moles on both sides of the equation. If there is an increase in pressure, the reaction favors the direction with a lower number of moles.
If there is a decrease in pressure, the reaction will favor the direction with more moles of molecules. Because there are 2 moles of substance on the left and 1 on the right, if the pressure is increased, the reaction will favor the side with a fewer moles of molecules, which in this case is the forward reaction.
A + b ↔ ab -when dealing with pressure, you need to count the number of moles on both side of the equation. if there is an increase in pressure, the reaction favors the direction with less number of moles. if there is a decrease in pressure, the reaction will favor the direction with more moles of molecules.
refer to pg 571-573 in your textbook
in answer choice a, there are 2 moles on the left and 1 mole of substance on the right. if the pressure is increased, the reaction will favor the side with less number of moles of molecules, which in this case is the forward reaction.