## Search found 32 matches

Sat Mar 16, 2019 10:34 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: w=-PdeltaW
Replies: 5
Views: 399

### w=-PdeltaW

Can someone explain when we use the equation w=-PdeltaW? I saw this equation but I do not know how to apply it.
Sat Mar 16, 2019 10:33 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: kB
Replies: 1
Views: 274

### kB

What is the value for kB, and will that value be provided?
Sat Mar 16, 2019 10:32 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: q and delta H
Replies: 6
Views: 546

### q and delta H

Hello, I was wonder if q and delta H are the same thing? Because I see them being use interchangeably.
Sun Mar 10, 2019 8:44 pm
Forum: Zero Order Reactions
Topic: Graphs
Replies: 8
Views: 725

### Graphs

Just to clarify, the graph for a first order ln[X] vs time and zero order [X] vs time reaction is a decreasing linear slope. For second order it is an increasing linear slope. Right? So when would they be the increasing and decreasing exponential graphs?
Sun Mar 10, 2019 8:31 pm
Forum: Second Order Reactions
Topic: Equations
Replies: 2
Views: 1587

### Equations

Does anyone know if we are expected to know how all of the kinetics equations were derived? Or should we just memorize them?
Sun Mar 10, 2019 8:22 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Final Material
Replies: 4
Views: 182

### Final Material

Hi, on the class website Dr. Lavelle said that the final exam material will consist of homework problems and online assessments. What online assessments is he referring to?
Sun Mar 03, 2019 8:31 pm
Forum: General Rate Laws
Replies: 3
Views: 204

Does anyone know if Dr. Lavelle curves the final grade?
Sun Mar 03, 2019 8:29 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Standard cell potential
Replies: 3
Views: 199

### Standard cell potential

For the equation -nFEcell=deltaG, how do we determine n?
Sun Mar 03, 2019 8:26 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Replies: 73
Views: 4089

Hello, so Dr. Lavelle has so many resources, which is great. However, it is impossible to attend everything. Does anyone have any recommendations for which office hours to go to? Like are the step up sessions most beneficial, or..? What do you recommend because I would like to spend my time in the b...
Sun Feb 24, 2019 7:40 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Example 4J.4 in 7th ed textbook
Replies: 1
Views: 105

### Example 4J.4 in 7th ed textbook

When they solve for delta H, why do they only use Fe2O3 and CO2 in the calculation?
Sun Feb 24, 2019 7:38 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibbs free energy units
Replies: 3
Views: 377

### Gibbs free energy units

What are the units for the standard Gibbs free energy of formation?
Sun Feb 24, 2019 7:36 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Example 4J.1 in 7th ed textbook
Replies: 1
Views: 91

### Example 4J.1 in 7th ed textbook

For under the "anticipate" section they state the that solid and liquid phases are in equilibrium. How can you tell just from the problem that they're in equilibrium?
Sun Feb 17, 2019 11:30 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibbs Free Energy
Replies: 5
Views: 222

### Gibbs Free Energy

Can someone explain what Gibbs Free Energy is? I understand the equations but I don't really know what it means conceptually.
Sun Feb 17, 2019 11:26 pm
Forum: Calculating Work of Expansion
Topic: Units for R
Replies: 10
Views: 659

### Units for R

For the R constant, what exactly are the units? I've always thought they were J/Kxmol but could it also be kJ/Kxmol?
Sun Feb 17, 2019 11:23 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Extensive Property
Replies: 3
Views: 402

### Extensive Property

Can someone please explain what an extensive property is?
Sun Feb 10, 2019 9:47 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Which does more work?
Replies: 3
Views: 130

### Which does more work?

Which system does more work, isothermal or reversible? And can someone explain why? I know he mentioned it many times in lecture but I am still confused.
Sun Feb 10, 2019 9:45 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Isothermal vs Reversible
Replies: 2
Views: 143

### Isothermal vs Reversible

Can someone explain the difference between isothermal and reversible systems? I understand that they require different equations but I do not know what the equations mean or when to use them.
Sun Feb 10, 2019 9:43 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Isothermal meaning
Replies: 4
Views: 227

### Isothermal meaning

What exactly does it mean for a system to be isothermal? I think the prof mentioned something about the heat being the same? I am confused.
Sun Feb 03, 2019 10:02 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: qv vs qp
Replies: 9
Views: 492

### qv vs qp

What is the difference between qv and qp and how do we know when we should use each of them?
Sun Feb 03, 2019 10:01 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Midterm
Replies: 12
Views: 459

### Midterm

Does anyone know what is the best way to study for the midterm? Also, does the professor hold any review sessions?
Sun Feb 03, 2019 9:59 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Quiz 1 Number 3c
Replies: 6
Views: 269

### Quiz 1 Number 3c

What were the units supposed to be for number 3 c on the 1st discussion quiz? Would it be atm because they are gasses?
Fri Jan 25, 2019 7:13 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: An element's standard state
Replies: 2
Views: 105

### An element's standard state

When talking about standard reaction enthalpies, how are we supposed to know what an element's standard state is? Like, what if we did not know that the standard state of H20 is liquid? Is that something we'd be given on an exam?
Fri Jan 25, 2019 2:31 pm
Forum: Phase Changes & Related Calculations
Topic: The qp symbol
Replies: 3
Views: 343

### The qp symbol

When describing the qp symbol, the professor said the q is the heat given off and p means that is it under conditions with a constant pressure. Does q also refer to the head absorbed? Or is it just for heat given off? And if so, is there a symbol we should know about for heat absorbed?
Fri Jan 25, 2019 2:28 pm
Forum: Phase Changes & Related Calculations
Topic: Enthalpy as a state property
Replies: 2
Views: 172

### Enthalpy as a state property

In lecture, the professor said that enthalpy is a state property. He also said that heat is not a state property. Enthalpy is the study of heat released or absorbed, so why is enthalpy a state property and heat isn't? Aren't they basically the same thing?
Fri Jan 25, 2019 2:23 pm
Forum: Phase Changes & Related Calculations
Topic: Due date for Discussion Questions
Replies: 8
Views: 392

### Due date for Discussion Questions

Is there a certain day and time that the discussion questions are due?
Thu Jan 17, 2019 7:59 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Net Ionic Equations for Equilibrium Constants
Replies: 2
Views: 108

### Net Ionic Equations for Equilibrium Constants

When are we supposed to use the net ionic equation when writing the equilibrium equation and constant?
Thu Jan 17, 2019 7:54 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Sig Figs
Replies: 3
Views: 150

### Sig Figs

Just to clarify.. And please correct me if I am wrong. Is the general rule for sig figs: for multiplication and division, keep the least amount of sigfigs that the problem has? For addition and subtraction: keep the least amount of decimal places that the problem has?
Thu Jan 17, 2019 7:50 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Weak and Strong Acids and Bases [ENDORSED]
Replies: 2
Views: 155

### Weak and Strong Acids and Bases[ENDORSED]

How are we supposed to know when a substance is a strong/weak acid/base? Should we just memorize a list online? Or will the question tell us?
Tue Jan 08, 2019 10:24 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Discussion Points
Replies: 3
Views: 155

### Discussion Points

Is there any way to see if we are getting credit for our discussion posts? I am not sure if I am doing these correctly and would like to see if I am getting points for it.
Tue Jan 08, 2019 10:20 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Compostition vs Concentration for Equilibrium
Replies: 2
Views: 153

### Compostition vs Concentration for Equilibrium

This is more of a technical/wording question, but is there a difference when they say that "at equilibrium, the concentrations are constant" vs "at equilibrium the compositions are constant"? I understand when they say that the concentrations are constant, but is composition the ...
Tue Jan 08, 2019 10:11 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Partial Pressures for Different Temperatures
Replies: 2
Views: 72

### Partial Pressures for Different Temperatures

For 5G.9 it asks whether the partial pressures will be the same in both containers when the second container has a higher molarity. I have the answer key and it says the partial pressures will be different, but I don't understand why. If each container is held at the same temperature, wouldn't the p...
Tue Jan 08, 2019 10:00 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 7th Edition - 5G.3 Mistake?
Replies: 3
Views: 147

### Re: 7th Edition - 5G.3 Mistake?

Hi, I had the same question. I checked the link for textbook mistakes and I did not see that problem on there. I thought we always had to balance the equation first? However, I just left it unbalanced because later on questions specify to balance the equation first and 5G.3 did not specify. I don't ...