New User Special Price Expires in

Let's log you in.

Sign in with Facebook


Don't have a StudySoup account? Create one here!


Create a StudySoup account

Be part of our community, it's free to join!

Sign up with Facebook


Create your account
By creating an account you agree to StudySoup's terms and conditions and privacy policy

Already have a StudySoup account? Login here

General Chem 1120 Study Guide Test 2

Star Star Star Star Star
1 review
by: Hayden Massey

General Chem 1120 Study Guide Test 2 CHEM 1120

Marketplace > Auburn University > Chemistry > CHEM 1120 > General Chem 1120 Study Guide Test 2
Hayden Massey

Preview These Notes for FREE

Get a free preview of these Notes, just enter your email below.

Unlock Preview
Unlock Preview

Preview these materials now for free

Why put in your email? Get access to more of this material and other relevant free materials for your school

View Preview

About this Document

A review of what chapters are going to be on Test 2
General Chemistry II
Ria Yngard
Study Guide
50 ?




Star Star Star Star Star
1 review
Star Star Star Star Star
"I love that I can count on (Hayden for top notch notes! Especially around test time..."
Ms. Lamar Bogan

Popular in General Chemistry II

Popular in Chemistry

This 6 page Study Guide was uploaded by Hayden Massey on Sunday March 20, 2016. The Study Guide belongs to CHEM 1120 at Auburn University taught by Ria Yngard in Spring 2016. Since its upload, it has received 38 views. For similar materials see General Chemistry II in Chemistry at Auburn University.


Reviews for General Chem 1120 Study Guide Test 2

Star Star Star Star Star

I love that I can count on (Hayden for top notch notes! Especially around test time...

-Ms. Lamar Bogan


Report this Material


What is Karma?


Karma is the currency of StudySoup.

You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!

Date Created: 03/20/16
Chemical Equilibrium: when the concentrations of reactants and products are persistent Equilibrium – highly dynamic; not static – no net change in products and reactants When reactants collide to make products, concentrations of reactants decrease, and the reaction rate decreases For a reverse reaction, the concentrations of reactants build up and the rate increases Injecting element into reactants = Speed Up BC of more collisions between molecules Reasons why concentrations remain unchanged when mixed: 1. Already at chemical equilibrium 2. Forward/Reverse reactions are so slow that you cant see the change When molecules have strong chemical bonds, mixtures exist where no change is seen over time BC the rates are so slow Law of Mass Action: jA + kB  lC + mD l m [C] [D] K = [A] [B]  Equilibrium Expression Where K is called the equilibrium constant Some Characteristics of the Equilibrium Expression: 1. Reverse reaction is reciprocal of original 2. Balanced Equation x N ; K new = ( K orininal ¿¿ 3. Apparent units of K are found by powers of various concentration The equilibrium constant always remains the same for a given equation, however the equilibrium concentrations may change depending on initial concentrations Equilibrium Position: a variation of equilibrium concentrations C = molar concentration of the gas = n/V = moles / volume jA + kB  mC P m K p c PAP Bk Kp is the equilibrium constant in terms of partial pressures K pK(RT ) Δ n where Δ n= L+M −(J+K) the “true” equilibrium constant involves the ratio of equilibrium pressure for a given substance to a reference pressure for that substance (ratio is activity of substance) Pi =a Activity = P i reference jA + kB  lC + mD aB ¿ ¿k a j¿ ( A ( )a ) m K= c D ¿ PcP Dm KP= j k PAP B K ≠ K P except for when the sum of the powers in the numerator and denominator are the same Homogeneous Equilibria: all products and reactants are gases Heterogeneous Equilibria: products and reactants are solids, liquids, aqueous, and/or gases A heterogeneous equilibrium’s position doesn’t depend on amount of pure solids or liquids present in equation Activity of a pure solid or liquid is always equal to 1 When pure solids and liquids are in a chemical reaction, their concentrations are not included in equilibrium expressions. The Extent of a Reaction If K is much greater than 1… - At equilibrium, the reaction is mostly products - Equilibrium is to the right - Essentially goes to completion If K is less than 1… - At equilibrium, the reaction is mostly reactants - Equilibrium is to the left - Reaction doesn’t occur to any significant extent The size of K and time required to reach equilibrium are not related Reaction Quotient Concentration of 1 product or reactant = 0, than system will shift in direction of the component that = 0 jA + kB  mC A ¿ ¿0 ¿ B ¿ where []0 is the initial concentration ¿ ¿0 ¿ ¿ m Q= [C]0 ¿ If Q = K, then system is at equilibrium If Q > K, then system shifts left to reach equilibrium If Q < K, then system shifts right to reach equilibrium 1. Write a balanced reaction and an equilibrium expression 2. List initial concentrations 3. Calculate Q and find shift 4. Define change needed to shift equilibrium with X’s and apply to initial concentration 5. Substitute new equations into equilibrium expressions and solve for X 6. Plug X value into equations to find equilibrium concentrations Initial Concentration Change Equilibrium Concentration A -X A – X B -X B - X C +2x C + 2x If 2 results are found, plug them into the equilibrium concentration expression. The equilibrium concentration expression cannot be a negative number. When X is small, you can assume that x = 0 and cancel it out of the equation. This only works if the value you get is within 5 % error If a change in conditions is imposed on a system at equilibrium, the equilibrium will shift in the direction that tends to reduce that change in conditions Increase concentration of Reactants = Q < K = Shift Right Increase concentration of Products = Q > K = Shift Left Decrease concentration of Reactants = Q > K = Shift Left Decreased concentration of Products = Q < K = Shift Right If reactant or product is a gas and is added to the system, the system will shift away from the added component If reactant of product is a gas and is removed from the system, the system will shift toward the removed component Effect of a Change in Pressure: 1. Add/Remove a gaseous reactant or product at constant volume 2. Add an inert gas not already in equation at constant volume 3. Change the volume of the container The addition of an inert gas at a constant volume causes no affect on the equilibrium position. It changes the total pressure, but not partial pressure or concentrations of reactants or products When the volume of a container is reduced, the system responds by reducing its volume by decreasing the total number of gaseous molecules in the system At constant temperature and pressure: volume of gas α number of moles of gas When the volume increases, the system will shift in the direction that increases its volume. Since the value of K changes with temperature, the effect of temperature on equilibrium is different If energy in the for of heat is added to the system, the shift will be in the direction that consumes energy Side with energy = decrease in concentration of elements on this side Side without energy = increases in concentration of elements If side with energy is with products, K decreases If side with energy is with reactants, K increases Endothermic Reactions: Increase in Temperature = Equilibrium Shift Right = K Value Increases Decrease in Temperature = Equilibrium Shift Left = K Value Decreases Exothermic Reactions: Increase in Temperature = Equilibrium Shift Left = K Value Decreases Decrease in Temperature = Equilibrium Shift Right = K Value Increases Treat energy as a reactant (for endothermic) or product (for exothermic) and predict the direction of the shift as if an actual reactant or product is added or removed jA + kB  mC P ¿ P obs B ¿ ¿ j (¿A ¿obs) ¿ ¿ ¿ (P ob) m KPObser=ed C ¿ KPobs is expected to increase with increasing total pressure BC the extra powers in the denominator greatens the error in pressures compared to numerator To find “true” value of K p , we measure K p at many various values of total pressure obs yiP i obs ai= P where yi is the activity coefficient for correcting Pi ref For equilibrium pressures > 1 atm, the value of Kp calculated from observed equilibrium pressures is expected to be within 1% of true value


Buy Material

Are you sure you want to buy this material for

50 Karma

Buy Material

BOOM! Enjoy Your Free Notes!

We've added these Notes to your profile, click here to view them now.


You're already Subscribed!

Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'

Why people love StudySoup

Steve Martinelli UC Los Angeles

"There's no way I would have passed my Organic Chemistry class this semester without the notes and study guides I got from StudySoup."

Anthony Lee UC Santa Barbara

"I bought an awesome study guide, which helped me get an A in my Math 34B class this quarter!"

Jim McGreen Ohio University

"Knowing I can count on the Elite Notetaker in my class allows me to focus on what the professor is saying instead of just scribbling notes the whole time and falling behind."

Parker Thompson 500 Startups

"It's a great way for students to improve their educational experience and it seemed like a product that everybody wants, so all the people participating are winning."

Become an Elite Notetaker and start selling your notes online!

Refund Policy


All subscriptions to StudySoup are paid in full at the time of subscribing. To change your credit card information or to cancel your subscription, go to "Edit Settings". All credit card information will be available there. If you should decide to cancel your subscription, it will continue to be valid until the next payment period, as all payments for the current period were made in advance. For special circumstances, please email


StudySoup has more than 1 million course-specific study resources to help students study smarter. If you’re having trouble finding what you’re looking for, our customer support team can help you find what you need! Feel free to contact them here:

Recurring Subscriptions: If you have canceled your recurring subscription on the day of renewal and have not downloaded any documents, you may request a refund by submitting an email to

Satisfaction Guarantee: If you’re not satisfied with your subscription, you can contact us for further help. Contact must be made within 3 business days of your subscription purchase and your refund request will be subject for review.

Please Note: Refunds can never be provided more than 30 days after the initial purchase date regardless of your activity on the site.