## Search found 55 matches

Fri Mar 15, 2019 10:21 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Test 2
Replies: 5
Views: 208

### Re: Test 2

How do you know that it is a neutral solution?
Thu Mar 14, 2019 10:10 am
Forum: Administrative Questions and Class Announcements
Topic: Final Questions
Replies: 10
Views: 549

### Re: Final Questions

He pulls questions from the homework, online assessments, and chemistry community- so keep that in mind!
Thu Mar 14, 2019 10:08 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Midterm Q3
Replies: 4
Views: 192

### Re: Midterm Q3

What section covers deprotonation?
Thu Mar 14, 2019 10:06 am
Forum: Balancing Redox Reactions
Topic: Balancing basic redox reactions
Replies: 7
Views: 433

### Re: Balancing basic redox reactions

Acidic solutions: balance O by using H2O, then H using H+
Basic solutions: balance O using H2O; then H using H2O (FOR EACH H) to the side of each half rxn that needs H and adding OH to the other side
Thu Mar 14, 2019 10:04 am
Forum: Zero Order Reactions
Topic: Zero order
Replies: 10
Views: 681

### Re: Zero order

Zero-order: a rxn for which the rate is independent of concentration of the reactant (Rate= k x (concentration)0 = k)
Thu Mar 14, 2019 10:02 am
Forum: Method of Initial Rates (To Determine n and k)
Topic: mmol vs mol
Replies: 6
Views: 473

### Re: mmol vs mol

If conversions are correct you should be fine, but I would keep in mind what units the problem gives.
Thu Mar 14, 2019 10:00 am
Forum: Student Social/Study Group
Topic: Curve?
Replies: 31
Views: 1345

### Re: Curve?

Last quarter w Lavelle, same grading system, I ended with 344/500 and that resulted in a C. I think it depends on the class averages.
Thu Mar 14, 2019 9:52 am
Forum: First Order Reactions
Topic: Writing First Order Reactions
Replies: 4
Views: 338

### Re: Writing First Order Reactions

What I do is write all of the exponents even if it is 0 or 1, but then I simply further and would take out the value to the 0 as it would be 1, and I would not write to the first power.
Wed Mar 13, 2019 8:16 am
Forum: Method of Initial Rates (To Determine n and k)
Topic: Determining the rate constant when given trials
Replies: 3
Views: 199

### Re: Determining the rate constant when given trials

15.17 The following rate data were collected for the reaction 2A(g) + 2B(g) +C(g) -> 3G(g) + 4F(g): Initial concentration (mmol.L^-1) Experiment [A]v0 [B]v0 [C]v0 Initial rate((mmol G).L^-1.s^-1) 1 10. 100. 700. 2.0 2 20. 100. 300. 4.0 3 20. 200. 200. 16 4 10. 100. 400. 2.0 5 4.62 0.177 12.4 ? a) wh...
Fri Mar 08, 2019 10:03 am
Forum: General Rate Laws
Topic: 15.3
Replies: 3
Views: 162

### Re: 15.3

Do you work backwards for part c? I am not sure what to do.
I have the rate of reaction of NO2, I know the coefficient of NO2 is 2.
Do I divide 6.5 x 10^-3 by 2? How does that give the unique rate of the whole reaction?
Tue Feb 26, 2019 4:13 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: #14.13 Part C (Sixth Edition)
Replies: 3
Views: 136

### Re: #14.13 Part C (Sixth Edition)

I did one half rxn in regards to the Cl2(g) and then the other in regards to H2(g), then when you combine the half rxns you get 2H+(aq) and 2Cl-(aq) on the product side which is also 2HCl
Tue Feb 26, 2019 4:06 pm
Forum: Balancing Redox Reactions
Topic: basic
Replies: 3
Views: 119

### Re: basic

Basic solutions: balance O using H2O; then H using H2O to the side of each half rxn that needs H and then adding OH to the other side.
If there ends up being H2O on both sides you simplify
Tue Feb 26, 2019 4:04 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: 6M.1 7th Ed
Replies: 1
Views: 57

### Re: 6M.1 7th Ed

(left) Anode: oxidation half rxn
(right) Cathode: reduction half rxn

Oxidation: Loss of e-
Reduction: Gain of e-
Tue Feb 26, 2019 4:01 pm
Forum: Balancing Redox Reactions
Topic: Question 14.1c 6th edition
Replies: 1
Views: 68

### Re: Question 14.1c 6th edition

I think this is a typo!
Tue Feb 26, 2019 3:51 pm
Forum: Balancing Redox Reactions
Topic: Balancing Rules for Redox Reactions
Replies: 3
Views: 143

### Re: Balancing Rules for Redox Reactions

Step 1 : identify whats being oxidized/reduced (Oxidation: Loss of e- → reducing agent, Reduction: Gain of e- → oxidizing agent) Step 2 : write the 2 skeletal, unbalanced equations Step 3 : balance all except O and H Step 4 : Acidic solutions: balance O by using H2O, then H using H+ Basic solutions...
Tue Feb 26, 2019 3:49 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: galvanic/voltaic
Replies: 2
Views: 85

### Re: galvanic/voltaic

In the 6th edition textbook on page 569 it states "Galvanic cells are also known as voltaic cells."
Tue Feb 26, 2019 3:44 pm
Forum: Balancing Redox Reactions
Topic: common charges
Replies: 2
Views: 104

### Re: common charges

If you mean oxidation numbers, these are the ones I try to keep in mind:

Hydrogen in all compounds is +1
Hydrogen in hydrides -1
Oxygen in peroxides -1
Group 1 elements in compounds +1
Group 2 elements in compounds +2
Halogens in group 1 and 2 compounds -1
Monoatomic ions same as their charge
Tue Feb 26, 2019 3:41 pm
Forum: Balancing Redox Reactions
Topic: Cell Diagram
Replies: 4
Views: 149

### Re: Cell Diagram

How do we know which one to add out of Pt(s) or C graphite?
Wed Feb 13, 2019 4:22 pm
Forum: General Science Questions
Topic: Midterm Formulas
Replies: 6
Views: 587

### Re: Midterm Formulas

He recently updated the given equations/constants page on the website, I assume that is what he is giving us for the test today. I suggest taking a look and to see if there are any you should remind yourself of. I noticed that the delta S vaporization and delta S fusion equations are not given to us...
Wed Feb 13, 2019 4:19 pm
Forum: Administrative Questions and Class Announcements
Topic: breakdown of midterm?
Replies: 4
Views: 169

### Re: breakdown of midterm?

On the Midterm important info it states, "Questions will come from the Homework, Online Assessments, and Chemistry Community."
Wed Feb 13, 2019 4:18 pm
Forum: Administrative Questions and Class Announcements
Topic: breakdown of midterm?
Replies: 4
Views: 169

### Re: breakdown of midterm?

At least one question comes from the homework problems given.
Tue Feb 12, 2019 4:01 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Definitions
Replies: 1
Views: 77

### Re: Definitions

I would suggest looking at the given constants/equations sheet so you know which ones are given versus ones you'll need to remember. From my experience with Lavelle's tests, they do not specifically ask "state the definition of ___", although it is important to know when to use what and wh...
Tue Feb 12, 2019 3:55 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm
Replies: 6
Views: 246

### Re: Midterm

Which lecture was the cutoff one for the midterm? Will there be material from 2/8/19 lecture on the midterm since that is the one that touched on gibbs free energy?
Fri Feb 08, 2019 9:55 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: 6th Edition Problem 8.21
Replies: 8
Views: 287

### Re: 6th Edition Problem 8.21

cp would be different for copper and water. Cp copper = o.38 J/Celsius*g and cp water is 4.18 J/Celsius*g

Kobe_Wright wrote:What would cp be in this equation?
Wed Feb 06, 2019 10:26 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Cup of Tea
Replies: 17
Views: 723

### Re: Cup of Tea

As defined in the textbook an open system can exchange matter and energy
Wed Feb 06, 2019 10:24 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Midterm [ENDORSED]
Replies: 49
Views: 1999

### Re: Midterm[ENDORSED]

Between going over notes, the modules, the homework problems you should be good to go. If you have any doubts utilize the normal weekly sessions and even the midterm review sessions.
Fri Feb 01, 2019 10:16 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: HW 8.11 part b
Replies: 2
Views: 137

### Re: HW 8.11 part b

For the change in volume (V2-V1) is it 2.4-1.2 or 1.2-1.2? What values do you get for part a and part b? The second experiment does more work because all energy is going into moving the piston (none is going into increasing the temperature because the experiment is an isothermic expansion). You can ...
Thu Jan 24, 2019 11:52 am
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: 6th Edition, 12.23
Replies: 2
Views: 340

### Re: 6th Edition, 12.23

Maybe because of sig figs its 6.8? It is weird that the book states 6.80
Fri Jan 18, 2019 10:16 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 11.39 6th edition
Replies: 4
Views: 183

### Re: 11.39 6th edition

Since it is composed of two different equations on the table, how does that work?
Thu Jan 17, 2019 1:35 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: problem 5I.11
Replies: 3
Views: 122

### Re: problem 5I.11

Please post the question!
Sun Dec 09, 2018 5:53 pm
Forum: DeBroglie Equation
Topic: Calculating Velocity
Replies: 9
Views: 877

### Re: Calculating Velocity

What is the units for momentum, p?
Sun Dec 09, 2018 5:50 pm
Forum: Limiting Reactant Calculations
Topic: moles of reagant
Replies: 4
Views: 450

### Re: moles of reagant

You go from grams to moles and then look at the moles required from the equation and multiply those values.
Sun Dec 09, 2018 5:48 pm
Forum: Administrative Questions and Class Announcements
Topic: Final Grade View
Replies: 7
Views: 425

### Re: Final Grade View

I think it is still viewed out of 500.
Sun Dec 09, 2018 5:47 pm
Forum: Administrative Questions and Class Announcements
Topic: Saying Thank You to Dr. Lavelle
Replies: 280
Views: 134517

### Re: Saying Thank You to Dr. Lavelle

Thank you for arranging so many sessions for us I greatly appreciate it.
Sun Dec 09, 2018 5:46 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: acid rain formula
Replies: 4
Views: 181

### Re: acid rain formula

will I get partial points for getting the reactants right but not the product?
Sun Dec 09, 2018 5:45 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Why HF is a weaker acid than HCl
Replies: 17
Views: 3282

### Re: Why HF is a weaker acid than HCl

Because of the length of the bond
Sat Dec 08, 2018 6:51 pm
Forum: Quantum Numbers and The H-Atom
Topic: Lyman, Balmer, Pascal
Replies: 10
Views: 717

### Re: Lyman, Balmer, Pascal

How would we see the Lyman and Balmer series on the final?
Mon Dec 03, 2018 11:35 am
Forum: Naming
Topic: Naming the Shape
Replies: 6
Views: 245

### Re: Naming the Shape

Personally I have to draw out the lewis structure so I can physically see the vsepr model (the AXE form).
Wed Nov 28, 2018 9:16 am
Forum: Determining Molecular Shape (VSEPR)
Topic: 4.15 6th Edition
Replies: 1
Views: 81

### Re: 4.15 6th Edition

4.15 Write the Lewis structure and the VSEPR formula, list the shape, and predict the approximate bond angles b) TeCL4 Te has 6 e-, Cl has 7e- times 4 = 28e-. 28+6= 34e-. Lewis structure must have 34e-. Lewis Structure: Te is the central atom, there are 4 Cl's around the Te, they all connect with a ...
Sat Nov 17, 2018 6:25 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Double and Triple Bonds
Replies: 2
Views: 86

### Re: Double and Triple Bonds

The second rule of the VSEOR model is: "Rule 2 There is no distinction between single and multiple bonds: a multiple bond is treated as a single region of high electron concentration. That is, the two electron pairs in a double bond stay together and repel other bonds or lone pairs as a unit. T...
Sat Nov 17, 2018 6:19 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR Chart
Replies: 3
Views: 149

### Re: VSEPR Chart

Thanks for this.
Sat Nov 17, 2018 6:18 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Radicals in Molecular Structure Notation
Replies: 2
Views: 59

### Re: Radicals in Molecular Structure Notation

I think BH2- has 6 electrons. B has 3, H2 has 2, and since it has the - charge it adds another electron, adding up to 6.
So the VSEPR formula would be AX2E1.
Sat Nov 17, 2018 6:11 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: tetrahedral vs trigonal planar
Replies: 9
Views: 476

### Re: tetrahedral vs trigonal planar

What helps me is looking at the VSEPR formula. They are distinct from one another.
Tue Oct 30, 2018 12:56 pm
Forum: Significant Figures
Topic: Exam
Replies: 6
Views: 745

### Re: Exam

You look at the givens and determine the one with the least amount of sig figs. Your answer should reflect that number of sig figs.

Ex: givens 5.12345, .00000023, and .12.
The least amount of sig figs is 2 in .12
So your answer should have 2 sig figs.

Hope this helps.
Fri Oct 26, 2018 9:47 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration Help
Replies: 3
Views: 169

### Electron Configuration Help

The last time I have seen electron configurations I was a sophomore in high school, when we first saw them in lecture I was very lost. I have tried watching videos to teach myself about them and I thought I started to understand but I was confused again when it came to the shorthand way of writing i...
Mon Oct 22, 2018 7:26 pm
Forum: SI Units, Unit Conversions
Topic: Remembering Unit Conversions
Replies: 5
Views: 436

### Re: Remembering Unit Conversions

Wait do we need to memorize these conversions? Do we also need to memorize the frequency conversions such as what one joule is in etc? I don't think we need to memorize these ones specifically, I asked my TA and he said we are going to see some prefixes more then others- like pico and nano. These o...
Fri Oct 19, 2018 9:15 pm
Forum: SI Units, Unit Conversions
Topic: Remembering Unit Conversions
Replies: 5
Views: 436

### Remembering Unit Conversions

Hello, I'd like to share how I remember unit conversions: King Henry Died Monday Drinking Chocolate Milk KHDMDCM Kilo Hecto Deka [Meters(liters/grams)] Deci Cent Mili 10^3 10^2 10^1 10^0 10^-1 10^-2 10^-3 The "Meters" section is also covers liters and grams. There is no prefix I know of fo...
Fri Oct 19, 2018 8:57 pm
Forum: Quantum Numbers and The H-Atom
Topic: Lyman, Balmer, Pascal
Replies: 10
Views: 717

### Re: Lyman, Balmer, Pascal

Would n never equal 4 or anything more then 3?
Fri Oct 19, 2018 8:51 pm
Forum: *Black Body Radiation
Topic: Test
Replies: 9
Views: 745

### Re: Test

Will Monday's lecture be on the test?
Rachel Dang 1H wrote:Blackbody radiation should not be on the test next week, the material that we have covered including today's lecture will be though.
Fri Oct 12, 2018 10:02 am
Forum: Administrative Questions and Class Announcements
Topic: How Should We Utilize Sampling
Replies: 3
Views: 195

### Re: How Should We Utilize Sampling

I saw this in the bundle that was recommend. But I got the textbook alone, do I have to invest in this?
Fri Oct 12, 2018 10:00 am
Forum: Administrative Questions and Class Announcements
Topic: Homework Week 2
Replies: 5
Views: 209

### Re: Homework Week 2

It's a good idea to pick 1 or 2 problems from not so current lectures as it keeps old info fresh in mind.
Fri Oct 12, 2018 9:51 am
Forum: SI Units, Unit Conversions
Topic: Homework for Week 2
Replies: 16
Views: 497

### Re: Homework for Week 2

904837647 wrote:What's the late policy for hw? I couldn't find it on Lavelle's syllabus, maybe i just missed it but I didn't realize hw was now being collected during discussion.

I had to speak to my TA about this, explain your confusion and maybe they will work with you or tell you what you should do.
Thu Oct 04, 2018 11:11 pm
Forum: Empirical & Molecular Formulas
Topic: When to double moles
Replies: 13
Views: 436

### Re: When to double moles

If the value was 1.37 and it has to be multiplied to get closer to a whole number, what would you multiple it by? x 3 would equal to 4.11, but x 2 would be 2.74.
Thu Oct 04, 2018 11:05 pm
Forum: SI Units, Unit Conversions
Topic: Scientific Notation
Replies: 11
Views: 493

### Re: Scientific Notation

And remember to use the least amount of sig figs from the given info.
Thu Oct 04, 2018 11:03 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Moles and Molar Mass
Replies: 10
Views: 252

### Re: Moles and Molar Mass

Helen Mejia 3F wrote:Hey, so consider using Avogadros number (6.022 x 10^23) and multiplying it by twice the radius (which would be 288 pm).

6.022 x 10^23) Ag x (288 pm x 10^-12)= 1.73 x 10^14

Why do you multiply the radius twice?

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