Search found 70 matches

by Dylan Mai 1D
Sat Mar 17, 2018 7:23 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Galvanic vs. Voltaic
Replies: 2
Views: 199

Re: Galvanic vs. Voltaic

I believe galvanic and voltaic cells are the same thing
by Dylan Mai 1D
Sat Mar 17, 2018 7:22 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Winter 2013 Midterm Q7
Replies: 1
Views: 179

Re: Winter 2013 Midterm Q7

I think if it were not at equilibrium they would ask you to calculate Q
by Dylan Mai 1D
Wed Mar 14, 2018 11:09 pm
Forum: Balancing Redox Reactions
Topic: Balancing in a basic solution
Replies: 4
Views: 2509

Re: Balancing in a basic solution

Yes we should know how to balance equations in basic conditions as well as acidic
by Dylan Mai 1D
Wed Mar 14, 2018 11:08 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Calculating Work
Replies: 2
Views: 137

Re: Calculating Work

Yes i think so because there is work being done against a constant external pressure, and therefore that equation is able to be used
by Dylan Mai 1D
Tue Mar 13, 2018 2:35 pm
Forum: Administrative Questions and Class Announcements
Topic: Organic Chem on Final
Replies: 9
Views: 530

Re: Organic Chem on Final

Yes also another reason is that anything he lectures on has the possibility to be on the final
by Dylan Mai 1D
Tue Mar 13, 2018 2:33 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Organic solvent
Replies: 1
Views: 92

Re: Organic solvent

Water is no longer the solvent, which means it is no longer in large excess, and therefore is included in the rate law
by Dylan Mai 1D
Tue Mar 06, 2018 12:12 am
Forum: Experimental Details
Topic: units
Replies: 4
Views: 423

Re: units

I do not think you have to convert to the standard mol.L^-1 unless the question explicitly asks. The book leaves it in other units in the answers if thats how the units were originally presented in the question I think
by Dylan Mai 1D
Tue Mar 06, 2018 12:11 am
Forum: Balancing Redox Reactions
Topic: Oxidizing Power
Replies: 2
Views: 125

Re: Oxidizing Power

Elements that have higher oxidizing power are more easily reduced, meaning they have a higher value of E naught. So you would look at the given values of E naught for each one, and the one with the highest value is the best oxidizing agent
by Dylan Mai 1D
Tue Mar 06, 2018 12:09 am
Forum: Method of Initial Rates (To Determine n and k)
Topic: 15.17
Replies: 1
Views: 110

Re: 15.17

The way to find out which reactions to work with is only through looking at the experiments and finding experiments where one concentration changes and everything that is needed to be held constant is held constant. The book uses experiments 2 and 3 because only the concentration of B is changed her...
by Dylan Mai 1D
Thu Mar 01, 2018 9:07 pm
Forum: First Order Reactions
Topic: First Order Graph
Replies: 11
Views: 362

Re: First Order Graph

Will we ever need to graph on a test?
by Dylan Mai 1D
Thu Mar 01, 2018 9:03 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Average rate [ENDORSED]
Replies: 6
Views: 468

Re: Average rate [ENDORSED]

Although usually, you report the rate as positive
by Dylan Mai 1D
Thu Mar 01, 2018 9:01 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Interpreting graphs [ENDORSED]
Replies: 3
Views: 399

Re: Interpreting graphs [ENDORSED]

Will we start working with catalysts directly in problems relating to kinetics in this class?
by Dylan Mai 1D
Tue Feb 20, 2018 7:27 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Potential and Spontanaeity
Replies: 2
Views: 126

Re: Cell Potential and Spontanaeity

It is spontaneous when cell potential is positive and not spontaneous when cell potential is negative
by Dylan Mai 1D
Tue Feb 20, 2018 7:25 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Chapter 14 Outline Questions
Replies: 1
Views: 95

Re: Chapter 14 Outline Questions

For if a metal will dissolve, my TA said that would have to do with comparing the E naught of the metal to the E naught of water. The one with the higher E naught will be the one reduced or dissolved. It has to do with question 14.57
by Dylan Mai 1D
Mon Feb 19, 2018 2:43 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 14.43
Replies: 1
Views: 87

14.43

“A tin electrode in 0.015 M Sn(NO3)2 (aq) is connected to a hydrogen electrode in which the pressure of H2 is 1.0 bar. If the cell potential is 0.057 V at 25 °C, what is the pH of the electrolyte at the hydrogen electrode?” Can someone explain the assumptions made in the solutions manual for this qu...
by Dylan Mai 1D
Mon Feb 19, 2018 12:59 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 14.29
Replies: 3
Views: 139

Re: 14.29

How do you know whether it’s acidic or basic? And then from there how do you know what phase it’s in?
by Dylan Mai 1D
Mon Feb 19, 2018 11:57 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 14.29
Replies: 3
Views: 139

14.29

14.29 says “Suppose that each of the following pairs of redox couples is joined to form a galvanic generat3 a current under standard conditions. Identify the oxidizing agent and the reducing agent, write a cell diagram, and calculate the standard cell potential. part a: Co 2+/ Co and Ti 3+/ Ti 2+“ H...
by Dylan Mai 1D
Sun Feb 18, 2018 9:14 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 14.17A
Replies: 1
Views: 109

14.17A

Are we expected to know how to answer this question without appendix 2B? The question is “write balanced half reactions for the redox reaction of an acidified solution of potassium permanganate and iron (III) chloride”
by Dylan Mai 1D
Sun Feb 18, 2018 8:59 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 14.15A
Replies: 4
Views: 182

14.15A

How do you know that the Anode reaction is AgBr + e- to Ag (s) + Br - and not Br2 + 2e- to 2Br-?
by Dylan Mai 1D
Sun Feb 18, 2018 8:36 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 14.13c
Replies: 1
Views: 93

14.13c

In this question, Cl2 is reduced to 2Cl-, but in the cell diagram, Cl- is written before Cl2. Why? Thank you!
by Dylan Mai 1D
Thu Feb 15, 2018 10:29 pm
Forum: General Science Questions
Topic: Battery voltage
Replies: 4
Views: 366

Re: Battery voltage

It could be that they go through many reactions or maybe it has to do with things like capacitors being in series or in parallel
by Dylan Mai 1D
Thu Feb 15, 2018 10:28 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Magnitude
Replies: 2
Views: 103

Re: Magnitude

I would guess that magnitude is something like their voltages
by Dylan Mai 1D
Thu Feb 15, 2018 10:27 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Delta G=-nFE
Replies: 5
Views: 975

Re: Delta G=-nFE

do you have an example of one of the problems that does this?
by Dylan Mai 1D
Fri Feb 09, 2018 8:40 pm
Forum: Administrative Questions and Class Announcements
Topic: Lecture Slides
Replies: 6
Views: 316

Re: Lecture Slides

does he not bruin cast?
by Dylan Mai 1D
Fri Feb 09, 2018 8:39 pm
Forum: Balancing Redox Reactions
Topic: Basic vs. Acidic
Replies: 6
Views: 177

Re: Basic vs. Acidic

have we learned any concepts where acidic or basic affects our calculations of enthalpy, entropy, or Gibbs free energy?
by Dylan Mai 1D
Fri Feb 09, 2018 8:37 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Entropy
Replies: 7
Views: 232

Re: Entropy

is there an entropy of fusion?
by Dylan Mai 1D
Sun Feb 04, 2018 11:03 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: 9.65
Replies: 2
Views: 113

Re: 9.65

Why can we not use the given delta S values in appendix 2A in this question?
by Dylan Mai 1D
Sat Feb 03, 2018 6:26 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Homework 9.5 [ENDORSED]
Replies: 11
Views: 451

Re: Homework 9.5 [ENDORSED]

what are the units for delta S? sometimes it is per mol and sometimes it is not. I assume this depends on the question?
by Dylan Mai 1D
Sat Feb 03, 2018 6:23 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Question on 9.15?
Replies: 1
Views: 68

Re: Question on 9.15?

I remember Lavelle answering a question in lecture about how even if the temperature raises, the difference (delta H) between the same reactants and products stays the same. Their individual enthalpies change, the difference between the enthalpies is for the most part the same
by Dylan Mai 1D
Sat Feb 03, 2018 6:20 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: syllabus
Replies: 4
Views: 197

Re: syllabus

I think Lavelle will address this more next week, but my TA said everything we have done so far will be on the midterm, and electrochemistry might be on the midterm
by Dylan Mai 1D
Mon Jan 29, 2018 5:49 pm
Forum: Administrative Questions and Class Announcements
Topic: Last quarters finals
Replies: 4
Views: 229

Re: Last quarters finals

do we get to keep our finals or do we have to stay there, view it, and then return it?
by Dylan Mai 1D
Fri Jan 26, 2018 1:35 pm
Forum: Calculating Work of Expansion
Topic: Homework 8.11
Replies: 6
Views: 254

Re: Homework 8.11

This formula may also be on the formula sheet when you need it for future tests
by Dylan Mai 1D
Fri Jan 26, 2018 1:06 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Calculating internal energy in isobaric reaction
Replies: 3
Views: 198

Re: Calculating internal energy in isobaric reaction

Can someone also explain what an isobaric reaction is?
by Dylan Mai 1D
Fri Jan 26, 2018 1:05 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Heat Capacities of monatomic gas and linear molecule
Replies: 2
Views: 131

Re: Heat Capacities of monatomic gas and linear molecule

I think they are just are experimentally found molar heat capacities for mono atomic gasses. They are also on the formula sheet that’s given
by Dylan Mai 1D
Sun Jan 21, 2018 10:35 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 8.101E
Replies: 1
Views: 96

8.101E

A technician carries out the reaction 2SO2(g) + O2(g) —> 2SO3 ... In part E, after we have calculated the enathaloy if the reaction and want to find out how much enthalpy has been exchanged, why do we only use the 0.030 mol of SO2 that’s been consumed to calculate the enthalpy if 0.015 mol of O2 was...
by Dylan Mai 1D
Sun Jan 21, 2018 10:10 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Problem 8.99
Replies: 6
Views: 258

Re: Problem 8.99

I think for something like this we would be provided values
by Dylan Mai 1D
Thu Jan 18, 2018 8:12 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: 8.31
Replies: 5
Views: 232

Re: 8.31

I believe you know because they say assume that krypton behaves as an ideal gas, and therefore you would have to use the constants 5/2R and 3/2R which are molar heat capacities
by Dylan Mai 1D
Thu Jan 18, 2018 8:07 pm
Forum: Student Social/Study Group
Topic: Homework Questions
Replies: 1
Views: 292

Re: Homework Questions

Honestly for this class it is best to just be safe to know all of them unless Lavelle or a TA said a certain topic or question was not going to be tested
by Dylan Mai 1D
Thu Jan 18, 2018 8:05 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Heat vs. Enthalpy
Replies: 5
Views: 191

Re: Heat vs. Enthalpy

so when using delta H, is it wrong for someone to refer to that as heat? delta H is enthalpy right?
by Dylan Mai 1D
Mon Jan 15, 2018 3:19 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 8.53 Part b
Replies: 1
Views: 119

8.53 Part b

Question 53 Part B: the reaction of 1.40 g of carbon monoxide with excess water vapor to produce carbon dioxide and hydrogen gases in a bomb calorimeter causes the temperature of the calorimeter assembly to rise from 22.113 degrees C to 22.799 degrees C. The calorimeter assembly is known to have a t...
by Dylan Mai 1D
Sun Jan 14, 2018 11:43 am
Forum: Administrative Questions and Class Announcements
Topic: Constants & Equations Sheet
Replies: 3
Views: 169

Re: Constants & Equations Sheet

Is it the same constants and equations sheet as 14A?
by Dylan Mai 1D
Sat Jan 13, 2018 2:42 pm
Forum: Phase Changes & Related Calculations
Topic: Phase Changes
Replies: 13
Views: 549

Re: Phase Changes

Are we supposed to know the specific terms for those phase changes listed above? Like fusion for example
by Dylan Mai 1D
Sat Jan 13, 2018 10:58 am
Forum: Phase Changes & Related Calculations
Topic: Heat Curve of Water
Replies: 3
Views: 178

Re: Heat Curve of Water

We only need to know this concept, not that actual values for this correct?
by Dylan Mai 1D
Fri Jan 12, 2018 9:45 pm
Forum: Phase Changes & Related Calculations
Topic: Methods of Enthalpy
Replies: 8
Views: 309

Re: Methods of Enthalpy

There are 3 methods we know of right now correct?
by Dylan Mai 1D
Mon Jan 08, 2018 12:50 pm
Forum: Administrative Questions and Class Announcements
Topic: Registering again
Replies: 1
Views: 132

Registering again

So if I was in 14A with Lavelle and already have a chem community account registered, do I need to re-register for 14B if I have the same discussion section?
by Dylan Mai 1D
Tue Nov 28, 2017 8:42 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: 17.29C
Replies: 1
Views: 121

17.29C

the answer to [Co(CN)5(OH2)]2 is aquapentacyanocobaltATE (III) ion. How do you know when there is an -ate attached at the end vs when the ending to a compound name is simply cobalt?
by Dylan Mai 1D
Tue Nov 28, 2017 8:37 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Drawing 3D structures
Replies: 1
Views: 138

Drawing 3D structures

On the test, will we have to draw 3D structures and if so, how do we know when to draw one as opposed to drawing a 2D lewis structure? The textbook questions do not really specify when they want a 2D or a 3D structure, but the solutions manual sometimes has 3D structures instead of 2D structures.
by Dylan Mai 1D
Tue Nov 28, 2017 8:33 pm
Forum: Hybridization
Topic: 4.95
Replies: 3
Views: 180

Re: 4.95

Will we be asked on the test to answer with the number in front of the hybridized orbital?
by Dylan Mai 1D
Tue Nov 28, 2017 1:03 am
Forum: Determining Molecular Shape (VSEPR)
Topic: 4.25 Solutions Manual Error? [ENDORSED]
Replies: 1
Views: 120

4.25 Solutions Manual Error? [ENDORSED]

Question 4.25 D asks for the lewis structure of SF4 and whether it is polar or non polar. In my solutions manual , it shows the lewis structure for SCl4. I know that this does not change the answer of polar or non polar, but wanted to check that the solutions manual shows the wrong lewis structure. ...
by Dylan Mai 1D
Mon Nov 27, 2017 11:49 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: question 4.17 [ENDORSED]
Replies: 1
Views: 146

question 4.17 [ENDORSED]

On question 4.17 it asks for the bond angles in ozone and the azide ion, and gives their respective formulas. will we ever be asked a question that doesn't provide the formulas?

thank you!
by Dylan Mai 1D
Mon Nov 27, 2017 10:23 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Question 4.3
Replies: 1
Views: 123

Question 4.3

On question 4.3b, it asks to draw and name the shape of CH2F2. How do you know if the atoms are coming in or out of the page, and how do you know that in this molecule, the hydrogens are the ones going in and out of the page?

thank you!
by Dylan Mai 1D
Mon Nov 27, 2017 10:16 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Question 4.1
Replies: 1
Views: 125

Question 4.1

Question shows two ball and stick diagrams for two molecules. One has an angle of 120 degrees and the other is linear with an angle of 180 degrees. It then asks whether there must be, may be, or cannot be one or more lone pairs on the central atom. How can you determine this with this info? thank you!
by Dylan Mai 1D
Sun Nov 19, 2017 8:25 pm
Forum: Sigma & Pi Bonds
Topic: drawing sigma/pi bonds
Replies: 6
Views: 340

Re: drawing sigma/pi bonds

we would just label the single, double, or triple bonds as sigma or pi bonds if asked right
by Dylan Mai 1D
Sun Nov 19, 2017 8:16 pm
Forum: SI Units, Unit Conversions
Topic: Derived Units
Replies: 4
Views: 310

Re: Derived Units

I usually keep units our of my calculations unless there are necessary conversions I need to do, and then I make sure to have correct units on my final boxed answer
by Dylan Mai 1D
Thu Nov 09, 2017 2:55 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Test 3, Question #1
Replies: 3
Views: 227

Re: Test 3, Question #1

the deltav is just (1.5+0.4)-(1.5-0.4). You could use the 1.5 in this calculation, or disregard it and just double 0.4 for your delta v
by Dylan Mai 1D
Tue Nov 07, 2017 6:45 pm
Forum: Ionic & Covalent Bonds
Topic: #25 on Chapter 3
Replies: 6
Views: 343

Re: #25 on Chapter 3

how do you figure out the charges on the atoms?
by Dylan Mai 1D
Tue Nov 07, 2017 6:44 pm
Forum: Ionic & Covalent Bonds
Topic: 3.25
Replies: 6
Views: 370

Re: 3.25

How do you know the charges for the elements? memorization?
by Dylan Mai 1D
Sat Oct 28, 2017 8:53 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Homework 2.37 [ENDORSED]
Replies: 7
Views: 2285

Re: Homework 2.37 [ENDORSED]

What exactly is Z subscript eff? I read about it in the textbook and still don't understand. Was it covered in lecture? I do not see it in my notes.
by Dylan Mai 1D
Sat Oct 28, 2017 11:56 am
Forum: *Particle in a Box
Topic: What is the equation: En= (n^2*h^2)/(8*m*L^2) used for? [ENDORSED]
Replies: 5
Views: 1306

Re: What is the equation: En= (n^2*h^2)/(8*m*L^2) used for? [ENDORSED]

Does anyone have an answer for the question above yet? I also do not remember seeing this formula in lecture
by Dylan Mai 1D
Sat Oct 28, 2017 11:54 am
Forum: Trends in The Periodic Table
Topic: Exceptions [ENDORSED]
Replies: 4
Views: 303

Re: Exceptions [ENDORSED]

Regarding periodic trend exceptions, at a peer learning session I learned that carbon and oxygen are exceptions to e- affinity and ionization energy respectively because carbon wants to gain 1 e- to have a half filled 2p and oxygen wants to lose an e- for the same reason
by Dylan Mai 1D
Sat Oct 21, 2017 1:14 pm
Forum: Administrative Questions and Class Announcements
Topic: Homework for Test #3
Replies: 1
Views: 194

Homework for Test #3

What are the homework problems exactly for this next test and material we are learning? Is it the rest of the Quantum World questions from the syllabus?
by Dylan Mai 1D
Mon Oct 16, 2017 11:40 pm
Forum: Photoelectric Effect
Topic: Hey I stumbled upon these questions. Please help!
Replies: 4
Views: 388

Re: Hey I stumbled upon these questions. Please help!

24 is A, Ultraviolet. I think I got this from my notes or one of the videos, but it also makes sense to have UV light be commonly used since it may have a better chance at ejecting electrons with its higher energy.
by Dylan Mai 1D
Mon Oct 16, 2017 11:39 pm
Forum: Photoelectric Effect
Topic: Hey I stumbled upon these questions. Please help!
Replies: 4
Views: 388

Re: Hey I stumbled upon these questions. Please help!

I believe 22 is A. If no electrons are ejected than that means there is not enough energy to eject the electron. To increase the energy, using a shorter wavelength/ higher frequency would increase the energy and potentially gain enough energy to eject an electron. E=hv, so with a higher frequency co...
by Dylan Mai 1D
Thu Oct 12, 2017 8:12 pm
Forum: Properties of Light
Topic: Wavelengths and Frequency of Electromagnetic Radiation [ENDORSED]
Replies: 7
Views: 457

Re: Wavelengths and Frequency of Electromagnetic Radiation [ENDORSED]

my TA said a good way to remember how ultraviolet is next to visible light on the 400nm side and how infrared light is on the 700nm side is by just looking at the names themselves. Ultraviolet is next to the violet side of visible light and infrared light is on the red side of visible light
by Dylan Mai 1D
Thu Oct 12, 2017 8:08 pm
Forum: Properties of Electrons
Topic: Balmer vs Lyman series [ENDORSED]
Replies: 5
Views: 485

Re: Balmer vs Lyman series [ENDORSED]

The wavelength values of the Balmer and Lyman series are something we should know for the test right? We are not given a spectrum if a question asks correct?
by Dylan Mai 1D
Tue Oct 03, 2017 11:42 am
Forum: Empirical & Molecular Formulas
Topic: F.1 textbook exercise
Replies: 3
Views: 287

Re: F.1 textbook exercise

Oh i see that we would just count the number of each element that appears in the molecular structure but how do we know the order of the elements in the formula? How do we know it is C10H16O instead of OH16C10? Thanks!
by Dylan Mai 1D
Tue Oct 03, 2017 11:37 am
Forum: Empirical & Molecular Formulas
Topic: F.1 textbook exercise
Replies: 3
Views: 287

F.1 textbook exercise

For F.1 we are given the molecular structure for Citral and we need to write the molecular formula from that. Is this something we need to know for the test friday and how do we do this question if so? Thank you!
by Dylan Mai 1D
Mon Oct 02, 2017 10:39 pm
Forum: Significant Figures
Topic: All students read this sig fig post [ENDORSED]
Replies: 116
Views: 10349

Re: All students read this sig fig post [ENDORSED]

I haven't seen anyone talk about this or maybe I missed the post, but on Lavelle's website there is a Sig Fig review document posted under the Text and Exam Schedule and the Solution Manual Errors link that helped me review Sig Figs!

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