Search found 52 matches

by JesseAuLec1Dis1G
Sat Mar 14, 2020 5:58 pm
Forum: Ideal Gases
Topic: 5% Rule
Replies: 6
Views: 44

Re: 5% Rule

The five percent rule is used in ICE tables. If the x value you get is 5% or less than the initial then you can ignore it. I believe that if the K is 10^-3 or less you can usually make this assumption.
by JesseAuLec1Dis1G
Sat Mar 14, 2020 5:55 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: What was your favorite chem topic?
Replies: 24
Views: 107

Re: What was your favorite chem topic?

I think it'd have to be equilibrium. For some reason ICE tables are so satisfying to me.
by JesseAuLec1Dis1G
Sat Mar 14, 2020 5:55 pm
Forum: Student Social/Study Group
Topic: Final Jitters
Replies: 118
Views: 24309

Re: Final Jitters

I just like to practice a lot. At the end of the day it's just one test one quarter out of one year here. At the end of the day, everything will work out fine. You've done your best.

I hope this helps. Good luck!
by JesseAuLec1Dis1G
Sat Mar 14, 2020 5:53 pm
Forum: Administrative Questions and Class Announcements
Topic: final exam - question
Replies: 6
Views: 103

Re: final exam - question

I think he just sent out an email about the logistics. It'll be submitted on ccle.
by JesseAuLec1Dis1G
Sat Mar 14, 2020 5:51 pm
Forum: Administrative Questions and Class Announcements
Topic: Saying Thank You to Dr. Lavelle
Replies: 275
Views: 115743

Re: Saying Thank You to Dr. Lavelle

Dr. Lavelle,

All of your extra resources and extra hours helped me so much!

Stay safe, and thank you for the quarter :)
by JesseAuLec1Dis1G
Mon Mar 09, 2020 1:00 am
Forum: General Rate Laws
Topic: Difference between each order of reaction
Replies: 3
Views: 24

Re: Difference between each order of reaction

It's based on the concentration not the amount. I'm also unsure why the overall reaction number the sum of all individual order reactions though in multiple reactions.
by JesseAuLec1Dis1G
Mon Mar 09, 2020 12:56 am
Forum: Student Social/Study Group
Topic: Final Exam Review
Replies: 4
Views: 53

Final Exam Review

Does anyone know if there's a final exam review held by the UAs like the pizzaroll review and does anyone know when and where that will be?
by JesseAuLec1Dis1G
Mon Mar 09, 2020 12:54 am
Forum: Second Order Reactions
Topic: [A] v. Time
Replies: 16
Views: 80

Re: [A] v. Time

It's linear for second order. Does anyone know when it wouldn't be linear?
by JesseAuLec1Dis1G
Mon Mar 09, 2020 12:53 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: gibbs free energy
Replies: 15
Views: 96

Re: gibbs free energy

It's the energy associated with a thermodynamic reaction that is available to do work.
by JesseAuLec1Dis1G
Mon Mar 09, 2020 12:52 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Ecell
Replies: 5
Views: 27

Re: Ecell

Ecello or Ecell naught is just in standard conditions.
by JesseAuLec1Dis1G
Sun Mar 01, 2020 10:48 pm
Forum: Balancing Redox Reactions
Topic: Acidic vs. Basic Solutions
Replies: 8
Views: 71

Re: Acidic vs. Basic Solutions

I think it's almost the same but in acidic reactions H+ is used to balance equations and in basic reactions OH- is used to balance equations.
by JesseAuLec1Dis1G
Sun Mar 01, 2020 10:43 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: when to use K or Q
Replies: 18
Views: 106

Re: when to use K or Q

Use Q when the reaction is not at equilibrium.
by JesseAuLec1Dis1G
Sun Mar 01, 2020 10:41 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cathode/Right & Anode/Left
Replies: 7
Views: 38

Re: Cathode/Right & Anode/Left

You can remember that the cathode is always reduction and the anode is always oxidation with this trick: "red cat" and "an ox" if that's helpful.
by JesseAuLec1Dis1G
Sun Mar 01, 2020 10:37 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: N value
Replies: 7
Views: 57

Re: N value

You just half to make sure that the number of electrons cancel out in both of the half reactions. But to answer your question yes it would be 2.
by JesseAuLec1Dis1G
Sun Mar 01, 2020 10:36 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Kinetics in Test 2?
Replies: 13
Views: 103

Re: Kinetics in Test 2?

So is test two only on the second page of outline 4 and all of outline 5?
by JesseAuLec1Dis1G
Fri Feb 21, 2020 1:26 pm
Forum: General Science Questions
Topic: What are Workshops?
Replies: 10
Views: 101

Re: What are Workshops?

I go to both workshops and step ups and it's kind of the same. You just work through practice problems in both. In some workshops though worksheets are given out which are really helpful.
by JesseAuLec1Dis1G
Fri Feb 21, 2020 1:24 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Voltage and Current
Replies: 2
Views: 18

Re: Voltage and Current

Current is the rate of flow of electric charge. Voltage is the potential difference in charge of two points in an electric field. So essentially the relationship between voltage and current is that voltage causes current in a sense.
by JesseAuLec1Dis1G
Fri Feb 21, 2020 1:18 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Ph
Replies: 8
Views: 75

Re: Ph

I've always been told in peer learning sessions that a given pH is the pH when the system is at equilibrium.
by JesseAuLec1Dis1G
Fri Feb 21, 2020 1:16 pm
Forum: Balancing Redox Reactions
Topic: Redox Proton Transfer
Replies: 3
Views: 27

Re: Redox Proton Transfer

Wouldn't the element change if a proton was lost?
by JesseAuLec1Dis1G
Fri Feb 21, 2020 1:13 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Voltage of 0
Replies: 3
Views: 22

Re: Voltage of 0

When the galvanic cell has a voltage of zero the current stops meaning the system is in equilibrium.
by JesseAuLec1Dis1G
Mon Feb 17, 2020 4:47 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Open Systems
Replies: 6
Views: 70

Re: Open Systems

I think most equations can. Most of the time though an open system is to be considered at constant pressure though.
by JesseAuLec1Dis1G
Mon Feb 17, 2020 4:46 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Cv vs Cp
Replies: 17
Views: 167

Re: Cv vs Cp

Cv is used when there's constant volume and Cp is used when there's constant pressure.
by JesseAuLec1Dis1G
Tue Feb 11, 2020 2:17 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: how to find a heat capacity when not given
Replies: 3
Views: 30

Re: how to find a heat capacity when not given

Usually there's information you can use to get there and then use q=nC(deltaT). A lot of the TA's and UA's also warn that you can usually use PV=nRT to get values you need that don't have yet.
by JesseAuLec1Dis1G
Tue Feb 11, 2020 2:14 pm
Forum: Student Social/Study Group
Topic: set up of the midterm
Replies: 4
Views: 53

Re: set up of the midterm

I haven't had a class with Lavelle but I think it might be kinda like the tests. Like there are questions with like different parts under it which are worth different points. I was told to look over the Pizza Roll review to get a good representation, but of course that review doesn't have every last...
by JesseAuLec1Dis1G
Tue Feb 11, 2020 2:11 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Constant R
Replies: 15
Views: 130

Re: Constant R

You just have to pay attention to the units of each. Just make sure your calculations cancel out units so you end up with the units you want when you've finished all of your calculations.
by JesseAuLec1Dis1G
Tue Feb 11, 2020 12:13 am
Forum: Phase Changes & Related Calculations
Topic: Work (w)
Replies: 8
Views: 56

Re: Work (w)

Work is dependent on the path taken. If you're on a football field and you push a sled to the 50 yard line, then you go back to the 30 yard line you do more work than someone who just pushes a sled to the 30 yard line, even though you end up in the same spot.
by JesseAuLec1Dis1G
Tue Feb 11, 2020 12:09 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: delta U = q + w
Replies: 6
Views: 40

Re: delta U = q + w

I think all of it is in terms of the system. So if the system is doing work than work is positive.
by JesseAuLec1Dis1G
Tue Feb 11, 2020 12:05 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Go=0
Replies: 7
Views: 51

Re: Go=0

Gibb's free energy is at zero when the reaction is at equilibrium.
by JesseAuLec1Dis1G
Mon Feb 10, 2020 11:58 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm grading
Replies: 8
Views: 95

Re: Midterm grading

I think they have assigned problems that they each have to grade.
by JesseAuLec1Dis1G
Mon Feb 10, 2020 11:58 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: isothermal
Replies: 2
Views: 25

Re: isothermal

Yes, which means that q=-w or -w=q
by JesseAuLec1Dis1G
Mon Feb 10, 2020 1:27 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: State Function
Replies: 7
Views: 34

Re: State Function

Since it is a state function it is not path dependent. This is why we can use Hess's law, because the pathway doesn't matter just the end results.
by JesseAuLec1Dis1G
Mon Feb 10, 2020 1:25 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: q rev
Replies: 9
Views: 59

Re: q rev

the subscript rev just signifies that the reaction is reversible.
by JesseAuLec1Dis1G
Mon Feb 10, 2020 1:22 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Spontaneous vs Favorable
Replies: 8
Views: 60

Re: Spontaneous vs Favorable

A favorable reaction is when energy is released, while a spontaneous reaction is when Gibbs free energy is negative.
by JesseAuLec1Dis1G
Mon Feb 10, 2020 1:21 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Stability and Bond Enthalpy
Replies: 3
Views: 26

Re: Stability and Bond Enthalpy

The bond enthalpy is the amount of energy needed to break the bond. So the tiger the bond enthalpy the more energy needed meaning more stable.
by JesseAuLec1Dis1G
Mon Feb 10, 2020 1:20 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: q=CΔT
Replies: 5
Views: 38

Re: q=CΔT

Yes you wouldn't need to include mass of moles if they're asking for the heat energy of the calorimeter or the heat capacity of the calorimeter.
by JesseAuLec1Dis1G
Mon Feb 10, 2020 1:13 pm
Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
Topic: Using Cv and Cp
Replies: 4
Views: 25

Using Cv and Cp

When calculating entropy do we always use Cv for constant volume and Cp for constant pressure?
by JesseAuLec1Dis1G
Sun Feb 09, 2020 12:25 am
Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
Topic: Going from delta S to delta H
Replies: 2
Views: 22

Going from delta S to delta H

What is the relationship from going from delta S to delta H? Like if you had delta S could you use it to calculate delta H as a state function?
by JesseAuLec1Dis1G
Sun Jan 26, 2020 9:21 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7951
Views: 1156854

Re: Post All Chemistry Jokes Here

Are you made of copper and tellurium? Because you're CuTe.
by JesseAuLec1Dis1G
Sun Jan 26, 2020 9:16 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5% Rule
Replies: 9
Views: 54

5% Rule

If I make the assumption because K is less than 10^-3, but the x value is less than 5% do I have to go back and use the quadratic formula to calculate x?
by JesseAuLec1Dis1G
Sun Jan 26, 2020 9:14 pm
Forum: Student Social/Study Group
Topic: Office Hours
Replies: 5
Views: 79

Re: Office Hours

I haven't. But the UA sessions can be very helpful!
by JesseAuLec1Dis1G
Sun Jan 26, 2020 9:11 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7951
Views: 1156854

Re: Post All Chemistry Jokes Here

This is hard. All the funny chemistry jokes argon >:)
by JesseAuLec1Dis1G
Sun Jan 26, 2020 9:11 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7951
Views: 1156854

Re: Post All Chemistry Jokes Here

Sb is antimony on the periodic table and how I remember it is Susan B Anthony >:)
by JesseAuLec1Dis1G
Sun Jan 19, 2020 10:19 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: ice table/quadratic
Replies: 6
Views: 50

Re: ice table/quadratic

If you get two positive values you should plug them both back in. If you subtract the value of x from the initial and get a negative value than use the other value of x.
by JesseAuLec1Dis1G
Sun Jan 19, 2020 10:13 pm
Forum: Ideal Gases
Topic: Using PV=nRT
Replies: 7
Views: 51

Re: Using PV=nRT

You would need to use this equation if you needed to convert mols to pressure.
by JesseAuLec1Dis1G
Sun Jan 19, 2020 10:10 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Effect of increasing pressure on reactions
Replies: 6
Views: 49

Effect of increasing pressure on reactions

Can someone explain to me what happens if you increase pressure on a reaction? Increasing pressure decreases volume so wouldn't products be favored? From my notes I have that increasing pressure doesn't favor products or reactants.
by JesseAuLec1Dis1G
Sun Jan 19, 2020 4:20 pm
Forum: Calculating the pH of Salt Solutions
Topic: Adding an Acid or Base in Water
Replies: 3
Views: 49

Adding an Acid or Base in Water

If someone were to add 1.0x10^-9 mol of HCL to water than why is it that the pH of the water doesn't change that much? Lavelle talked about this in lecture but I'm not sure I fully understand.
by JesseAuLec1Dis1G
Sun Jan 19, 2020 4:15 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Reaction Shifts Left or Right
Replies: 15
Views: 88

Re: Reaction Shifts Left or Right

In this reaction heat is on the product side of the reaction. So when you increase the temperature(increase heat) you increase the amount of product. The reaction will shift towards the reactants or shift left.
by JesseAuLec1Dis1G
Sun Jan 12, 2020 10:38 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Concentration
Replies: 6
Views: 49

Re: Concentration

The units aren't used because molarity isn't considered over an amount of time. K is a constant so time is not considered.
by JesseAuLec1Dis1G
Sun Jan 12, 2020 10:21 pm
Forum: Ideal Gases
Topic: Topics on Test 1
Replies: 37
Views: 268

Re: Topics on Test 1

I heard it was going to be on objectives from outline one for sure, but I was told it may not be all of the objectives in outline 2 if all the material isn't covered in lecture.
by JesseAuLec1Dis1G
Sun Jan 12, 2020 9:51 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Values of K and Meaning
Replies: 3
Views: 32

Values of K and Meaning

If K>1 this means there are more products at equilibrium and if K<1 this means there are more reactants at equilibrium. But there is also the values discussed in lecture where if K>10^3 products are strongly favored and if K<10^-3 reactants are favored. What's the difference between there being more...
by JesseAuLec1Dis1G
Sun Jan 12, 2020 9:40 pm
Forum: Student Social/Study Group
Topic: Peer Learning Sessions in Young Hall
Replies: 5
Views: 62

Peer Learning Sessions in Young Hall

When do the Peer Learning Sessions in Young Hall start and will different material be presented in different days of the week?
by JesseAuLec1Dis1G
Sun Jan 12, 2020 9:35 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: 5% rule
Replies: 12
Views: 280

Re: 5% rule

The five percent rule allows you to get out of using the quadratic formula when doing ice tables. Be sure to check if the x value you get is smaller than 5% of the initial value to get out of using the quadratic formula

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