Le Chatelier's Principle

[Victoria Luu - 1C]

Why does looking at the difference of moles to determine which side is favored work for the change in pressure? Do the rules also apply to the change in volume as well?

[davidbakalov_lec2_2L]

Looking at the difference in moles only works for reactions in which the products and reactants are gaseous. Such reactions typically prefer the direction in which the pressure is lowest, which in this case is when as few moles as possible are present.

[Faith Fredlund 1H]

Looking at the moles in an equation to determine the direction the reaction will favor due to a change in pressure at a constant temperature implies that there is a change in volume, unless it is states that an inert gas is added to a container with a constant volume. The reaction will favor the side with the least amount of moles because Le Chatelier's Principle states that a system in equilibrium will try to minimize the effect a constraint has upon that system; in this way it will attempt to reduce the pressure on one side of the reaction by pushing it to whatever direction contains the least amount of moles.

[Tessa Lawler 1A]

Just in case this helps focus your studying - while understanding the basic concept is important, Dr. Lavelle did mention in lecture that we don't need to know Le Chatelier's principle.