## Search found 32 matches

Sun Mar 17, 2019 12:00 am
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Kinetics Plots
Replies: 5
Views: 444

### Re: Kinetics Plots

But if you have a plot of [reactant] vs time for a first order reaction then in that case you'll get an exponential curve which is decreasing.
Sat Mar 16, 2019 11:57 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Rate Determining Step
Replies: 9
Views: 481

### Re: Rate Determining Step

What happens if the slow step has an intermediate in it?
Sat Mar 16, 2019 11:28 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Activated complex
Replies: 4
Views: 378

### Re: Activated complex

I am still unsure about what an activated complex model is. Could someone clarify?
Thu Mar 07, 2019 1:12 pm
Forum: General Rate Laws
Topic: Rate laws
Replies: 2
Views: 125

### Rate laws

What is the difference between a differential rate law and an integrated rate law?
Thu Mar 07, 2019 1:08 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Problem 6.57 - 7th edition
Replies: 1
Views: 78

### Re: Problem 6.57 - 7th edition

I have another question about this problem. The solution manual says that Ka = sqrt(K), but I don't remember learning this. How do we know this?
Thu Mar 07, 2019 1:06 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Problem 6.57 - 7th edition
Replies: 1
Views: 78

### Problem 6.57 - 7th edition

The solution of this problem mentions the formula ln K = nFE/RT.
I am not sure how to get to this formula.
Sat Mar 02, 2019 3:14 pm
Forum: General Rate Laws
Topic: Unique rates
Replies: 5
Views: 236

### Re: Unique rates

Yes, because the unique rate is an instantaneous rate which means it is different at each point in time.
Sat Mar 02, 2019 3:10 pm
Forum: General Rate Laws
Topic: rate law
Replies: 3
Views: 126

### Re: rate law

It mainly allows us to identify the speed at which a reaction occurs, in particular the rate at which reactants decrease and products form.
Sat Mar 02, 2019 3:03 pm
Forum: General Rate Laws
Topic: Differential rate law
Replies: 1
Views: 113

### Differential rate law

In what cases do we use the differential rate law formula, K[R]^n?
Sun Feb 24, 2019 9:48 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Oxidation number
Replies: 2
Views: 106

### Oxidation number

What is the oxidation number?
Tue Feb 19, 2019 11:04 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gr and Gp from lecture
Replies: 2
Views: 128

### Gr and Gp from lecture

In the lecture from February 15th, Dr Lavelle wrote in his notes that "If Gr different from Gp, then the system (reaction) is not at equilibrium." I just want to make sure that r is for reactants and p for products.
Tue Feb 19, 2019 10:58 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Delta Srxn
Replies: 4
Views: 555

### Delta Srxn

In the formula for delta Srxn, we have the sum of the products of Sm minus the sum of the reactant of Sm.
I'm confused about what the "m" of Sm is.
Sun Feb 17, 2019 10:32 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Converting to q rev
Replies: 4
Views: 206

### Re: Converting to q rev

When the change in entropy is reversible, you can also use delta S = nrln(V2/V1) or delta S = nCln(P1/P2) because pressure is inversely related to volume.
Sun Feb 17, 2019 10:21 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Enthalpy
Replies: 4
Views: 335

### Re: Enthalpy

Delta S=q/T so since temperature is the denominator, if you make T bigger, delta S will be smaller and vice versa, if you make T smaller, delta S will be bigger. That explains why the change in entropy is larger when the temperature is lower.
Sun Feb 17, 2019 10:11 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Gibbs Free Energy in relation to H and S
Replies: 3
Views: 137

### Re: Gibbs Free Energy in relation to H and S

And just as a reminder, a state property is not dependent on the path taken to obtain that state.
Sat Feb 09, 2019 5:19 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: 2nd and 3rd law of thermodynamics
Replies: 1
Views: 113

### 2nd and 3rd law of thermodynamics

What are the 2nd and 3rd law of thermodynamics be if we summarize them in a sentence each?
Sat Feb 09, 2019 5:13 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Gibbs free energy
Replies: 2
Views: 112

### Gibbs free energy

Are we only going to have to calculate the change in Gibbs free energy, or will we ever have to calculate the actual Gibbs free energy for a certain point?
Sat Feb 09, 2019 5:08 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Degeneracy
Replies: 8
Views: 279

### Re: Degeneracy

I am still confused as to what exactly the difference between degeneracy and entropy? Don't both of these concepts relate to disorder in a system?
Sun Feb 03, 2019 6:36 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm Review
Replies: 14
Views: 503

### Re: Midterm Review

Dr Lavelle just sent an email today I believe with all the dates and times for midterm review sessions this coming week.
Sun Feb 03, 2019 6:19 pm
Forum: Administrative Questions and Class Announcements
Replies: 179
Views: 12475

Could someone explain the detailed reasoning for questions 2.a. and b. on worksheet 1?
Sun Feb 03, 2019 5:55 pm
Forum: Phase Changes & Related Calculations
Topic: Type of systems
Replies: 12
Views: 525

### Type of systems

Is an isolated system always closed?
Sun Feb 03, 2019 4:28 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Thermo Test/Midterm
Replies: 9
Views: 277

### Re: Thermo Test/Midterm

I don't think they will be given to us since learning and knowing basic Lewis structures was gone over in Chem 14A.
Tue Jan 29, 2019 6:52 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 7th edition 6D.3
Replies: 1
Views: 317

### 7th edition 6D.3

In number a of 6D.3, the solution manual gives the Ka of chlorous acid and it says [HClO2] is 0.10-0.06, 0.06 being the concentration of HClO2's conjugate base, ClO2-. I don't understand why it's 0.10-0.06 and not just 0.10.
Sun Jan 27, 2019 11:20 pm
Forum: Phase Changes & Related Calculations
Topic: Different enthalpy calculation methods
Replies: 4
Views: 135

### Different enthalpy calculation methods

Are there specific cases in which we should use one of the three methods over the others to calculate delta H?
Sun Jan 27, 2019 10:50 pm
Forum: Phase Changes & Related Calculations
Topic: reversible/irreversible
Replies: 8
Views: 217

### Re: reversible/irreversible

No, I believe combustion is never reversible, no matter the circumstances. The C02 and water formed cannot react to reform the fuel and oxygen, so the reaction is always irreversible.
Sun Jan 27, 2019 10:47 pm
Forum: Phase Changes & Related Calculations
Topic: Delta Hº versus delta H
Replies: 2
Views: 122

### Delta Hº versus delta H

In lecture, Prof Lavelle alternates between delta H and delta Hº. Is there a difference between the two? If there is, I which situation should I use which symbol?
Sun Jan 27, 2019 10:47 pm
Forum: Phase Changes & Related Calculations
Topic: Delta Hº versus delta H
Replies: 7
Views: 686

### Delta Hº versus delta H

In lecture, Prof Lavelle alternates between delta H and delta Hº. Is there a difference between the two? If there is, I which situation should I use which symbol?
Tue Jan 15, 2019 8:29 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Question Focus 5I.17 7th edition
Replies: 1
Views: 40

### Question Focus 5I.17 7th edition

I looked at the solution for this question and the manual says "The concentration of N2 and O2 remain practically the same at 0.114 mol/L". I don't understand how we can come to this solution. Could someone enlighten me?
Thu Jan 10, 2019 9:33 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Clarification from lecture 1 - Jan 7th
Replies: 3
Views: 116

### Clarification from lecture 1 - Jan 7th

I was absent on the day of the first lecture, so there is something in the notes I received that I don't quite understand. When we are given the example of a forward reaction with N2 and H2 as reactants and NH3 as the product. We calculate the Kc for the forward reaction by replacing the Kc formula ...
Thu Jan 10, 2019 9:31 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Clarification from lecture 1 - Jan 7th
Replies: 2
Views: 76

### Clarification from lecture 1 - Jan 7th

I was absent on the day of the first lecture, so there is something in the notes I received that I don't quite understand. When we are given the example of a forward reaction with N2 and H2 as reactants and NH3 as the product. We calculate the Kc for the forward reaction by replacing the Kc formula ...
Thu Jan 10, 2019 9:19 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Definition of equilibrium
Replies: 4
Views: 99

### Definition of equilibrium

Could I have a clarification on what it means exactly when a reaction reaches equilibrium? Thank you
Tue Oct 02, 2018 11:13 am
Forum: Molarity, Solutions, Dilutions
Topic: Pre-Module Assessment Q23 and Q25
Replies: 2
Views: 428

### Pre-Module Assessment Q23 and Q25

Hello, I am having a difficult time figuring out how to solve the two following questions: "23. 5.00 g of KMnO4 is dissolved in a 150.00 mL flask of water. If 20.00 mL of this solution is removed and placed in a new 2nd 250.00 mL flask and filled with water, what is the concentration of the sol...