Search found 44 matches

by Eva Guillory 2E
Sun Mar 17, 2019 4:30 pm
Forum: Van't Hoff Equation
Topic: Van't hoff
Replies: 2
Views: 230

Re: Van't hoff

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by Eva Guillory 2E
Sun Mar 17, 2019 4:28 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Catalysts
Replies: 9
Views: 275

Re: Catalysts

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by Eva Guillory 2E
Sun Mar 17, 2019 4:24 pm
Forum: Administrative Questions and Class Announcements
Topic: Final Grade Release Date?
Replies: 7
Views: 370

Final Grade Release Date?

Does anyone have an idea of when the final grades will be released?
by Eva Guillory 2E
Sun Mar 10, 2019 9:32 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Order for Cell Diagram
Replies: 4
Views: 55

Re: Order for Cell Diagram

In addition, my ta told me that Lavelle prefers you put the aqueous elements closer to the double line (salt bridge) in the middle, and platinum (if included) on the outside.
by Eva Guillory 2E
Sun Mar 10, 2019 9:29 pm
Forum: Administrative Questions and Class Announcements
Topic: Final Questions
Replies: 10
Views: 364

Re: Final Questions

Considering the midterm and past finals, it will probably be somewhere between 8 to 10 questions.
by Eva Guillory 2E
Sun Mar 10, 2019 9:25 pm
Forum: Zero Order Reactions
Topic: Graphs
Replies: 8
Views: 156

Re: Graphs

Here is a diagram that you might find helpful:
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by Eva Guillory 2E
Sun Mar 03, 2019 11:17 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Does anyone know if test 2 will be curved?
Replies: 15
Views: 310

Re: Does anyone know if test 2 will be curved?

Here is what Lavelle said in the syllabus: "Each test and exam has a total score but is not assigned a grade. Only at the end of the class when the class average score (out of 500 points) is known are final grades assigned. This class does not use a curve." So, its probably not very likely...
by Eva Guillory 2E
Sun Mar 03, 2019 11:12 pm
Forum: General Rate Laws
Topic: Difference between First Order Reactions and Second Order Reactions
Replies: 1
Views: 48

Re: Difference between First Order Reactions and Second Order Reactions

https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Kinetics/Experimental_Methods/Methods_of_Determining_Reaction_Order has some useful descriptions to help differentiate them: "In a first-order reac...
by Eva Guillory 2E
Tue Feb 26, 2019 4:37 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Platinum in cell diagrams
Replies: 4
Views: 755

Re: Platinum in cell diagrams

This makes sense, but I'm confused, because for the answer of 6L.5 part b in the 7th edition (which i listed below), despite Iodine being a solid, platinum is still included? In the solution manual, it does say that "An inert electrode such as Pt is necessary when both oxidized and reduced spec...
by Eva Guillory 2E
Tue Feb 26, 2019 12:09 am
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: 6L.3 7th Edition: Solve for E° values?
Replies: 1
Views: 56

6L.3 7th Edition: Solve for E° values?

For problem 6L.3 in the 7th edition, how are we supposed to find the E° values of the cathode and anode? Is there an index in the back of the book that we are supposed to look the values up in, or do we just solve for them using an equation? In addition, if we do have to solve for them, what equatio...
by Eva Guillory 2E
Sun Feb 24, 2019 7:57 pm
Forum: Balancing Redox Reactions
Topic: Oxidation and Reduction?
Replies: 6
Views: 88

Re: Oxidation and Reduction?

In a redox reaction, oxidation involves a loss of electrons, and reduction involves a gain of electrons. Some mnemonic devices that might be helpful include: LEO the lion says GER, where LEO = Loss of Electrons is Oxidation and GER = Gain of Electrons is Reduction OIL RIG, where OIL = Oxidation Is L...
by Eva Guillory 2E
Sun Feb 24, 2019 7:49 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibbs Free Energy
Replies: 7
Views: 128

Re: Gibbs Free Energy

http://image.slidesharecdn.com/tang05-entropyandgibbsfreeenergy-120209095951-phpapp01/95/tang-05-entropy-and-gibbs-free-energy-13-638.jpg?cb=1422605471 What do exergonic and endergonic mean? In a reaction, exergonic means that energy is released to the surroundings, and endergonic means that energy...
by Eva Guillory 2E
Sun Feb 24, 2019 7:46 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Spontaneous?
Replies: 6
Views: 93

Re: Spontaneous?

Here is a table that might help:
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by Eva Guillory 2E
Sun Feb 24, 2019 7:44 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibbs free energy units
Replies: 3
Views: 213

Re: Gibbs free energy units

Gibbs free energy is measured in units of kJ/mol
by Eva Guillory 2E
Sun Feb 24, 2019 7:34 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Endothermic Reactions Spontaneous
Replies: 2
Views: 59

Re: Endothermic Reactions Spontaneous

Here is a table which might help:
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by Eva Guillory 2E
Sun Feb 17, 2019 9:28 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Nonexpansion Work
Replies: 2
Views: 63

Re: Nonexpansion Work

viewtopic.php?t=9861

In summary, "Expansion work is pressure-volume work, and nonexpansion work is anything else (electrical, friction, motional, etc.)."
by Eva Guillory 2E
Sun Feb 17, 2019 8:56 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: delta G
Replies: 3
Views: 56

Re: delta G

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by Eva Guillory 2E
Tue Feb 12, 2019 1:35 am
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Homework Problem 4f.7 7th edition
Replies: 1
Views: 50

Homework Problem 4f.7 7th edition

I'm confused on 4F.7 a, because I keep getting 6.65 J*K^-1 rather than 6.80 J*K^-1. Is this most likely due to rounding differences? If so, if anyone got 6.80 J*K^-1, can you mention what values you rounded to? Oh, and for reference, here is what my problem looks like, which also lines up with the s...
by Eva Guillory 2E
Sun Feb 10, 2019 2:43 pm
Forum: General Science Questions
Topic: Thermodynamics in the Work Field
Replies: 2
Views: 228

Thermodynamics in the Work Field

I'm just curious, what are some common applications of thermodynamics in the work field? In addition, are there any specific examples of thermodynamics in relation to life sciences?

Edit: To clarify, I meant "work" in reference to occupation, not work in the thermodynamical sense.
by Eva Guillory 2E
Sun Feb 10, 2019 2:35 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7606
Views: 1017613

Re: Post All Chemistry Jokes Here

Honestly, it's kinda hard to come up with clever jokes for this thread. All the good ones argon.
by Eva Guillory 2E
Sun Feb 10, 2019 2:30 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Using Bond Enthalpies
Replies: 2
Views: 52

Re: Using Bond Enthalpies

In addition, here is a chart with some common average bond enthalpies if you need it:
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by Eva Guillory 2E
Sun Feb 10, 2019 2:27 pm
Forum: Calculating Work of Expansion
Topic: Integrals
Replies: 3
Views: 65

Re: Integrals

No, I don't believe so.
Some further comments about this equation were made in the topic below:
viewtopic.php?f=129&t=41797&hilit=integral
by Eva Guillory 2E
Sun Feb 10, 2019 2:23 pm
Forum: Phase Changes & Related Calculations
Topic: Enthalpy values
Replies: 3
Views: 68

Re: Enthalpy values

In addition, here is a chart with specific values pertaining to water:
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by Eva Guillory 2E
Fri Feb 01, 2019 1:52 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Isolated Systems
Replies: 6
Views: 91

Isolated Systems

Regarding Isolated systems (other than the example of the entire universe, which Lavelle mentioned in class), is there any way we can prove that other so-called isolated systems are actually 100% isolated?
by Eva Guillory 2E
Fri Feb 01, 2019 1:41 pm
Forum: Phase Changes & Related Calculations
Topic: PΔV of Solids and Liquids
Replies: 4
Views: 99

PΔV of Solids and Liquids

I understand that when solids and liquids are concerned in relation to the reaction constant P, PΔV is considered insignificant, but why is a change in volume ignored in cases involving substances like water, which visibly increases in volume when frozen?
by Eva Guillory 2E
Wed Jan 30, 2019 1:31 pm
Forum: Phase Changes & Related Calculations
Topic: Water phase change graph
Replies: 6
Views: 93

Re: Water phase change graph

Image
In this graph, the straight lines represent phase changes (where temperature is constant), and the slanted lines represent an increase in temperature.
by Eva Guillory 2E
Wed Jan 30, 2019 1:28 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Lecture
Replies: 5
Views: 94

Re: Lecture

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by Eva Guillory 2E
Wed Jan 30, 2019 1:22 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Standard State
Replies: 3
Views: 55

Re: Standard State

In addition, when pure elements are in their standard states, their standard enthalpies of formation are equal to zero, which makes solving for the enthalpy of a reaction easier.
by Eva Guillory 2E
Wed Jan 30, 2019 1:15 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Heat vs. Temp
Replies: 9
Views: 275

Re: Heat vs. Temp

Temperature indicates the random motion of particles.
Heat is the transfer of energy due to a temperature difference.

In summary, Temperature represents particle motion, and Heat represents energy transfer.
by Eva Guillory 2E
Sun Jan 27, 2019 10:00 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Enthalpy
Replies: 1
Views: 36

Re: Enthalpy

Yes, it does apply to both forward and reverse reactions.

This forum post helps to flesh out why enthalpies vary depending of the method of calculation you use:
https://chemistry.stackexchange.com/que ... n-the-calc
by Eva Guillory 2E
Fri Jan 25, 2019 1:57 am
Forum: Phase Changes & Related Calculations
Topic: State functions
Replies: 4
Views: 69

Re: State functions

In addition, here is an article about the difference between heat and temperature, and why they're not interchangeable: https://www.khanacademy.org/science/chemistry/thermodynamics-chemistry/internal-energy-sal/a/heat In addition, http://www.physicstutorials.org/home/heat-temperature-and-thermal-exp...
by Eva Guillory 2E
Fri Jan 25, 2019 1:53 am
Forum: Phase Changes & Related Calculations
Topic: State functions
Replies: 4
Views: 69

Re: State functions

According to http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch5/work.php: "Heat and work are not state functions. Work can't be a state function because it is proportional to the distance an object is moved, which depends on the path used to go from the initial to the final state. If work...
by Eva Guillory 2E
Fri Jan 25, 2019 1:41 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Units When Calculating Equilibrium Constant
Replies: 4
Views: 75

Re: Units When Calculating Equilibrium Constant

In addition, since K is equal to mol*L^-1 divided by mol*L^-1, the units will cancel out, leaving a unitless constant K.
by Eva Guillory 2E
Mon Jan 21, 2019 1:36 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Strong acids and bases
Replies: 4
Views: 69

Re: Strong acids and bases

Yeah, it is probably best to just memorize the list of the 7 strong acids and 8 strong bases.
Here is a link to a list if you need it: http://www.austincc.edu/chemlab/strongacidbase
by Eva Guillory 2E
Mon Jan 21, 2019 1:26 pm
Forum: Bronsted Acids & Bases
Topic: Sig Figs
Replies: 3
Views: 224

Re: Sig Figs

I doubt you would get a whole lot of points taken off, but I know Professor Lavelle posted a resource on the class website going over sig fig rules if you want to brush up on them.
by Eva Guillory 2E
Sun Jan 13, 2019 6:38 pm
Forum: Ideal Gases
Topic: Units
Replies: 3
Views: 70

Re: Units

According to google... torr = "a unit of pressure used in measuring partial vacuums, equal to 133.32 pascals" bar = "a unit of pressure equivalent to 100,000 newtons per square meter or approximately one atmosphere" atm = "a unit of pressure defined as 101,325 Pa" pasca...
by Eva Guillory 2E
Fri Jan 11, 2019 4:27 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Inert Gases
Replies: 2
Views: 55

Re: Inert Gases

Actually, I don't think that an inert gas affects the equilibrium constant at all because if the pressure of a reaction vessel is increased by adding an inert gas, the moles of reactant/product and the volume remain constant. Essentially, unless there is a change in reactant/product concentration, t...
by Eva Guillory 2E
Thu Jan 10, 2019 6:28 pm
Forum: Ideal Gases
Topic: HW # 5G.5 7th edition
Replies: 2
Views: 85

Re: HW # 5G.5 7th edition

If you look at page three of the syllabus, you will notice that 5G.5 is not included in the list of homework problems.
by Eva Guillory 2E
Thu Jan 10, 2019 6:24 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5G.5
Replies: 2
Views: 70

Re: 5G.5

If you look at page three of the syllabus, you will notice that 5G.5 is not included in the list of homework problems.
by Eva Guillory 2E
Thu Jan 10, 2019 6:21 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Pure solids and liquids in eq. constants [ENDORSED]
Replies: 4
Views: 109

Re: Pure solids and liquids in eq. constants [ENDORSED]

Pure solids and liquids are not included in equilibrium constants because the molar concentration of those substances does not change in reactions. In the case of aqueous solutions, H2O is not included in the constant equation because the overall change in the solvent concentration is insignificant ...

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