Le Chatelier's Principle

[Mingzi Yang 1E]

How much do we need to know about Le Chatelier's Principle for the upcoming midterm?

[Jonathan Batac - 2D]

As per the outline for Equilibrium on Lavelle's website: "Use Le Chatelier's principle to predict how the equilibrium composition of a reaction mixture is affected by: adding or removing reagents; compressing or expanding a gaseous mixture; and by raising or lowering the temperature." Basically, know how a system will respond to concentration changes, volume/pressure changes, and temperature changes.

[haley f]

It's my understanding that we just have to know what he covered in lecture, which was basically how pressure/volume, temperature, and concentration changes affect the equilibrium of the reaction!

[Sabine Salvucci 2E]

I think we just have to know what's on the outline/what he covered in lecture. You should probably know the relationship between volume/pressure, concentration, and temperature changes and equilibrium.

[Nathan Tong 3G]

In general, you should probably know how the changes listed above will affect the equilibrium, such as shifting to the left or right. I don't believe we have to calculate the exact changes but knowing which direction it shifts is important.

[Arnav Saud 2C]

The main thing you need to understand from the principle is how volume, pressure and temperature changes are applied to Le Chatelier's Principle.
You primarily should know that if you increase temperature in an exergonic reaction, it means that reactants will be favored, and if you increase the temperature of an endergonic reaction, it means that products will be favored,
Additionally, if you increase pressure, the system will favor the side with less moles of gas.
If you increase the volume of a system, the system will favor the side with more moles of gas.

[apurva-3E]

A good bit should be covering this topic.

[Ellison Gonzales 1H]

Could someone clarify how we check our “x” after using the 5 percent rule? Also, is the 5 percent rule a part of Le chatelier’s principle? Thanks

[Kushaal Madadi 2F]

I think we have to understand the concept because it is applicable in a variety of scenarios.

[Carlos Martinez 2K]

If I remember correctly we only need to understand the effects of pressure, temp and volume on a system! basically what he covered in lecture.

[Madilyn Schindler 3E]

Could someone clarify how we check our “x” after using the 5 percent rule? Also, is the 5 percent rule a part of Le chatelier’s principle? Thanks

The 5% rule basically just means that if the percent ionization if below 5% then x can be ignored, but if it's above 5% then you have to use the quadratic formula to solve for x. I don't think the 5% rule is really related to Le Chatelier's Principle but I could be wrong.

[Lilly Catarozoli 1B]

I think just how pressure, volume, temperature, and concentration changes the equilibrium of a reaction.

[Megan Hulsy 1A]

As everyone said, it's just what is on the outline, which is considering concentration, pressure/volume, and temperature. :)

[Mingzi Yang 1E]

Could someone clarify how we check our “x” after using the 5 percent rule? Also, is the 5 percent rule a part of Le chatelier’s principle? Thanks

I don't think the 5% rule is a part of Le Chatelier's principle.

[Mingzi Yang 1E]

Thank you for all the responses. These clarified my question!

[Anastasia Yulo 1C]

Mastering the questions given on the outlines regarding le Chatlier's principle would best prepare for the midterm according to the website information :-)

[Danielle DIS2L]

I think for this one you would just need to know the basic concepts such as how the reaction would be affected if there is an increase of concentration, pressure, volume and temperature.

[Neel Sharma 3F]

I would know the concept of relieving stress and how it applies to equilibrium and in some ways in Electrochem etc. Hope this helps!

[Arnav Saud 2C]

I think knowing the relationship of how equilibrium can change in terms of the Laws for Le Chatelier's Principle is important. (Changing temperature, pressure, volume, amount of reactants or products and how it will effect the way the system will act.)

[YuditGaribay3J]

I believe we have to be able to answer conceptually how pressure/volume, temperature, and concentration changes affect the equilibrium.

[Rachael Cohen 3G]

Like others have said, I believe we only have to know how pressure, volume, temperature, and adding or removing species in the reaction affect equilibrium.

Pressure/Volume:
Compressing a gas mixture will decrease its volume, increasing its pressure, and equilibrium will shift towards the side of the reaction with the fewest moles of gas.
Expanding a gas mixture will increase its volume, decreasing its pressure, and equilibrium will shift towards the side of the reaction with the most moles of gas.

Adding/Removing Species:
Adding a species will shift the equilibrium to the opposite side.
Removing a species will shift the equilibrium towards that side.

Temperature:
Based on whether the reaction is endo or exothermic, we know if heat is acting as a product or a reactant. Increasing the temperature adds heat, and we can treat it like adding a species in the reaction. Decreasing the temperature removes heat, and we can treat it like removing a species in the reaction.

[IshanModiDis2L]

I think we just had to know, like most things what was covered on the outlines and in lecture.