Search found 97 matches

by Hana Sigsbee 3B
Sat Feb 27, 2021 1:07 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: week 8 sapling #17
Replies: 2
Views: 38

week 8 sapling #17

What would the potential of a standard hydrogen electrode (S.H.E.) be under the given conditions?

[H+]=0.46 MPH2=4.9 atm T=298 K

Hi does anyone know what section of the textbook I could reference to try and solve this because honestly I have no clue where to start with this one.
by Hana Sigsbee 3B
Sat Feb 27, 2021 1:04 pm
Forum: Balancing Redox Reactions
Topic: sapling week 8 #18
Replies: 4
Views: 50

sapling week 8 #18

"One of the most recognizable corrosion reactions is the rusting of iron. Rust is caused by iron reacting with oxygen gas in the presence of water to create an oxide layer. Iron can form several different oxides, each having its own unique color. Red rust is caused by the formation of iron(III)...
by Hana Sigsbee 3B
Sat Feb 27, 2021 1:02 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: sapling week 8 #15
Replies: 3
Views: 41

sapling week 8 #15

"Calculate the cell potential for the reaction as written at 25.00 °C , given that [Cr2+]=0.791 M and [Fe2+]=0.0140 M . Use the standard reduction potentials in this table. Cr(s)+Fe2+(aq)↽−−⇀ Cr2+(aq)+Fe(s)" I think the part I may be doing wrong on this is calculating either Q or n but I a...
by Hana Sigsbee 3B
Sat Feb 27, 2021 1:01 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: sapling week 8 #12
Replies: 2
Views: 42

sapling week 8 #12

"Calculate the standard free-energy change for the reaction at 25 ∘C. Refer to the list of standard reduction potentials. 2Au3+(aq)+3Ni(s)↽−−⇀2Au(s)+3Ni2+(aq)" So far every time I have tried this problem I have gotten wildly different answers because I gave tried it multiple ways but they ...
by Hana Sigsbee 3B
Sat Feb 27, 2021 12:59 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: week 8 sapling #9
Replies: 1
Views: 23

week 8 sapling #9

"A galvanic (voltaic) cell consists of an electrode composed of iron in a 1.0 M iron(II) ion solution and another electrode composed of copper in a 1.0 M copper(I) ion solution, connected by a salt bridge. Calculate the standard potential for this cell at 25 °C. Refer to the list of standard re...
by Hana Sigsbee 3B
Sat Feb 27, 2021 12:57 pm
Forum: Balancing Redox Reactions
Topic: week 8 sapling #5
Replies: 1
Views: 44

week 8 sapling #5

"Identify the oxidizing and reducing agents in the skeletal (unbalanced) reaction. Then, balance the reaction, including the phase (solid, liquid, etc.) of each species. The reaction takes place in basic aqueous solution. Cl2O7(g)+H2O2(aq)⟶ClO−2(aq)+O2(g) Identify the oxidizing and reducing age...
by Hana Sigsbee 3B
Sat Feb 27, 2021 12:55 pm
Forum: Balancing Redox Reactions
Topic: #3 week 8 sapling
Replies: 2
Views: 16

#3 week 8 sapling

"For a particular redox reaction, NO is oxidized to NO−3 and Cu2+ is reduced to Cu+ . Complete and balance the equation for this reaction in basic solution. The phases are optional." Hi, I am having a hard time with this question for some reason, could someone give me some guidance on how ...
by Hana Sigsbee 3B
Sun Feb 21, 2021 10:42 pm
Forum: Student Social/Study Group
Topic: grades
Replies: 4
Views: 65

grades

Hi, so I know that the minimum to pass with a C- is 50% but I was wondering, does anyone know what the grade scale is after that?
by Hana Sigsbee 3B
Sun Feb 21, 2021 10:39 pm
Forum: Administrative Questions and Class Announcements
Topic: Extra homework problems on Midterm 2
Replies: 14
Views: 148

Re: Extra homework problems on Midterm 2

All the problems that relate to each topic are listed under the outlines on the syllabus but those obviously will not all be on the exams.
by Hana Sigsbee 3B
Sun Feb 21, 2021 10:37 pm
Forum: Administrative Questions and Class Announcements
Topic: Final
Replies: 34
Views: 102

Re: Final

I personally did not do great either and I reviewed sapling, textbook, outlines, lecture notes, and went to review sessions but I feel I would have done better if I was more engaged with the studying and not just doing it like I am going through the motions.
by Hana Sigsbee 3B
Sun Feb 21, 2021 10:32 pm
Forum: Balancing Redox Reactions
Topic: Oxidizing vs Reducing
Replies: 55
Views: 126

Re: Oxidizing vs Reducing

I try to remember it as oxidize is losing and reducing is gaining, so the oxidizing part gains the electron but the reducing part loses and electron.
by Hana Sigsbee 3B
Sun Feb 21, 2021 10:29 pm
Forum: Balancing Redox Reactions
Topic: coefficients for oxidation number
Replies: 22
Views: 80

Re: coefficients for oxidation number

No, I don't think so, I think the coefficient balances the equation but is not part of the calculation.
by Hana Sigsbee 3B
Sat Feb 20, 2021 7:03 pm
Forum: Student Social/Study Group
Topic: Post Midterm 2 De-stressing
Replies: 92
Views: 259

Re: Post Midterm 2 De-stressing

haha that's so funny, that's exactly what I did. The new episode of WandaVision was crazy.
by Hana Sigsbee 3B
Sat Feb 13, 2021 11:15 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm Material
Replies: 10
Views: 40

Re: Midterm Material

Dr.Lavelle emailed saying...
Midterm 2 will not cover any electrochemistry.



Midterm 2 covers:



Outline 3: Thermochemistry (but not the MT1 topics*)


Outline 4: Thermodynamics


*The MT1 topics (different ways of calculating reaction enthalpy) are not covered in MT2.
by Hana Sigsbee 3B
Sat Feb 13, 2021 11:14 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm 2 Content
Replies: 18
Views: 104

Re: Midterm 2 Content

Dr.Lavelle emailed saying that "Midterm 2 will not cover any electrochemistry.

Midterm 2 covers:

Outline 3: Thermochemistry (but not the MT1 topics*)

Outline 4: Thermodynamics"
by Hana Sigsbee 3B
Sat Feb 13, 2021 11:04 pm
Forum: Administrative Questions and Class Announcements
Topic: struggling
Replies: 73
Views: 271

struggling

Hi, so I am struggling in this class. I do all the problems outlined on the syllabus, I watch and rewatch lectures, I take notes on and read the entirety of the textbook sections but I got a pretty bad score on my midterm. Does anyone have any suggestions on what else I could be doing for better ret...
by Hana Sigsbee 3B
Sat Feb 13, 2021 10:55 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Sapling #5 week 5 and 6
Replies: 13
Views: 58

Sapling #5 week 5 and 6

The molar heat capacity for carbon monoxide at constant volume is CV, m=20.17 J/(K·mol) . An 8.00 -L fixed-volume flask contains CO(g) at a pressure of 2.00 kPa and a temperature of 25.0 °C. Assuming that carbon monoxide acts as an ideal gas and that its heat capacity is constant over the given temp...
by Hana Sigsbee 3B
Sat Feb 13, 2021 10:08 pm
Forum: Student Social/Study Group
Topic: Culinary Chemistry
Replies: 72
Views: 456

Re: Culinary Chemistry

This is so fun, I noticed the application of chemistry a lot in baking like baking is such an exact science because it's basically just chemical reactions coming together to make the end product, and if you get one of those reactions just a little off the whole thing is wrong.
by Hana Sigsbee 3B
Mon Feb 08, 2021 12:01 am
Forum: Administrative Questions and Class Announcements
Topic: Grades for Chemistry Community
Replies: 21
Views: 115

Re: Grades for Chemistry Community

The grading was input for week 5 as well even though week 5 was not done, Dr Lavelle sent an email talking about it. I got scared too.
by Hana Sigsbee 3B
Mon Feb 08, 2021 12:01 am
Forum: Administrative Questions and Class Announcements
Topic: Tips for Concentrating during a test
Replies: 31
Views: 112

Re: Tips for Concentrating during a test

I find a quiet room and just do my best to toon everything out, I know its hard sometimes though.
by Hana Sigsbee 3B
Mon Feb 08, 2021 12:00 am
Forum: Administrative Questions and Class Announcements
Topic: sapling
Replies: 4
Views: 7

sapling

do we know when the rest of the sapling assignments for the quarter will be posted? I know it's a little soon since we haven't started the next topics I just like having it all written out in my planner.
by Hana Sigsbee 3B
Sun Feb 07, 2021 11:59 pm
Forum: Administrative Questions and Class Announcements
Topic: midterm 2
Replies: 12
Views: 59

midterm 2

is midterm 2 cumulative or does it just cover everything we will have covered since midterm 1?
by Hana Sigsbee 3B
Sun Feb 07, 2021 11:58 pm
Forum: Administrative Questions and Class Announcements
Topic: exam review
Replies: 6
Views: 19

exam review

Hi, do we attend any office hours to review our exams?
by Hana Sigsbee 3B
Sun Jan 31, 2021 2:37 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Memorize bond enthalpies / standard enthalpies of formation?
Replies: 38
Views: 112

Re: Memorize bond enthalpies / standard enthalpies of formation?

No, my TA has said we do not need to memorize these and that if we ever need to use them they will be provided.
by Hana Sigsbee 3B
Sun Jan 31, 2021 2:35 pm
Forum: Administrative Questions and Class Announcements
Topic: Labs
Replies: 10
Views: 49

Labs

Hi, I was wondering when other people are planning on taking 14Bl and 14CL because I am not sure what the best planning would be to work them into my schedule, when do most people take those classes?
by Hana Sigsbee 3B
Sun Jan 31, 2021 2:32 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: closed system
Replies: 43
Views: 275

Re: closed system

A closed system prevents volume change because there is no exchange of matter with the system's surroundings so nothing can leave the system so its volume stays consistent.
by Hana Sigsbee 3B
Sun Jan 31, 2021 2:31 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Significance of open, closed, isolated
Replies: 22
Views: 414

Re: Significance of open, closed, isolated

Knowing the type of system is important so you are aware if there is any exchange in matter or energy with the system's surroundings because if there is an exchange that would affect the makeup of the system.
by Hana Sigsbee 3B
Sun Jan 31, 2021 2:29 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: isolated system examples
Replies: 4
Views: 20

Re: isolated system examples

since an isolated system does not exchange energy or matter with its surroundings an example Dr.Lavelle gave during the lecture was a really well-insulated thermos.
by Hana Sigsbee 3B
Sun Jan 24, 2021 4:56 pm
Forum: Administrative Questions and Class Announcements
Topic: Question about 14B Exams
Replies: 38
Views: 240

Re: Question about 14B Exams

Midterm 1 covers Chemical Equilibria, Acid and Base Equilibria, and only these Week 3 topics (4D.3; 4D.4; 4D.5; 4E.3). Last quarter it was structured so whichever topic we spent the most time on would have a larger portion of the test so it was proportional to the class.
by Hana Sigsbee 3B
Sun Jan 24, 2021 4:53 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm 1 Material?
Replies: 8
Views: 46

Re: Midterm 1 Material?

Dr.Lavelle emailed saying that "midterm 1 covers Chemical Equilibria, Acid and Base Equilibria, and only these Week 3 topics (4D.3; 4D.4; 4D.5; 4E.3)."
by Hana Sigsbee 3B
Sun Jan 24, 2021 4:52 pm
Forum: Administrative Questions and Class Announcements
Topic: Periodic Tables on Midterm
Replies: 23
Views: 88

Re: Periodic Tables on Midterm

yes, we print out the equations sheet and periodic table from Dr. Lavelle's website to use on the tests.
by Hana Sigsbee 3B
Sun Jan 24, 2021 4:51 pm
Forum: Phase Changes & Related Calculations
Topic: Endothermic v. Exothermic
Replies: 107
Views: 340

Re: Endothermic v. Exothermic

Yes, endothermic reactions will always have a positive delta H because the change is positive and exothermic reactions will always have a negative delta H because the change is negative.
by Hana Sigsbee 3B
Sun Jan 24, 2021 4:49 pm
Forum: Administrative Questions and Class Announcements
Topic: midterm
Replies: 11
Views: 62

midterm

Has Dr.Lavelle told us if we will be using a zoom for proctoring of the midterms?
by Hana Sigsbee 3B
Sat Jan 16, 2021 6:43 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Change in pressure due to inert gas
Replies: 6
Views: 48

Re: Change in pressure due to inert gas

An inert gas changes the total pressure of the entire system, it has no effect on the partial pressures of the individual components of the system.
by Hana Sigsbee 3B
Sat Jan 16, 2021 6:40 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Le Chatelier's Principle
Replies: 19
Views: 135

Re: Le Chatelier's Principle

My little "dumbed down" version of it that I remember it with is essential that if the system is acted on it will compensate for that but doing more of the opposite action to keep the original K value.
by Hana Sigsbee 3B
Sat Jan 16, 2021 6:38 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Using the ICE table
Replies: 36
Views: 146

Re: Using the ICE table

yes, personally I know ICE tables are used when doing these calculations but I like to use them on most problems just to keep everything organized and make sure I'm not missing anything
by Hana Sigsbee 3B
Sat Jan 16, 2021 6:37 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: ICE table and Molarity units
Replies: 18
Views: 73

Re: ICE table and Molarity units

Hi, I would use mol/L just to have consistency and prevent any little mistakes later on.
by Hana Sigsbee 3B
Thu Jan 14, 2021 10:48 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Getting two positive x values when using quadratic
Replies: 43
Views: 213

Re: Getting two positive x values when using quadratic

if both x values are positive one will likely be too big to be an option, like it will be larger than the concentration of one of the reactants or products so in that case, you would use the smaller x value.
by Hana Sigsbee 3B
Thu Jan 14, 2021 10:47 pm
Forum: Administrative Questions and Class Announcements
Topic: midterms
Replies: 7
Views: 71

midterms

Hi, I know last quarter for 14B we did our midterms at our discussion section times, does anyone know if we will be continuing to do so this quarter?
by Hana Sigsbee 3B
Sun Jan 10, 2021 2:14 pm
Forum: Ideal Gases
Topic: Non-Ideal gases?
Replies: 26
Views: 154

Re: Non-Ideal gases?

I believe Dr.Lavelle has said we do not use non-ideal gases in the course but possibly in some upper-division chemistry courses we might.
by Hana Sigsbee 3B
Sun Jan 10, 2021 2:10 pm
Forum: Ideal Gases
Topic: Ideal Gas Definition
Replies: 10
Views: 70

Re: Ideal Gas Definition

we assume all gases are ideal gases even though very few are but by assuming so we are able to use PV=nRT
by Hana Sigsbee 3B
Sun Jan 10, 2021 1:59 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Reaction Quotient Definition
Replies: 7
Views: 45

Re: Reaction Quotient Definition

we find Q instead of K when the reaction is not at equilibrium. Q can be used to compare to a given K to find if the reaction favors products or reactants.
by Hana Sigsbee 3B
Sun Jan 10, 2021 1:48 pm
Forum: Ideal Gases
Topic: reversing reactions
Replies: 83
Views: 461

Re: reversing reactions

when a reaction is reversed K is inversed as 1/K
by Hana Sigsbee 3B
Sun Jan 10, 2021 1:44 pm
Forum: Ideal Gases
Topic: Kc vs Kp
Replies: 109
Views: 1004

Re: Kc vs Kp

The c in Kc refers to concentration and the p in Kp refers to pressure so for equations referring to gases you would use Kp as it refers to the pressure of the gas.
by Hana Sigsbee 3B
Sun Jan 10, 2021 1:41 pm
Forum: Student Social/Study Group
Topic: Advice for someone who didn't take 14A with professor Lavelle
Replies: 61
Views: 350

Re: Advice for someone who didn't take 14A with professor Lavelle

what I found to be most useful was ensuring I did all the assigned bookwork and then before exams making my own study guide out of questions from each topic that was assigned and doing even more practice.
by Hana Sigsbee 3B
Sat Dec 12, 2020 5:54 pm
Forum: Student Social/Study Group
Topic: Taking the final on an iPad
Replies: 4
Views: 54

Re: Taking the final on an iPad

I think you would be able to as long as you're in the lockdown browser otherwise I do not think you can because you would be able to access other materials on it.
by Hana Sigsbee 3B
Sat Dec 12, 2020 5:52 pm
Forum: Calculating the pH of Salt Solutions
Topic: Questions About Organizing Solutions by pH
Replies: 2
Views: 46

Re: Questions About Organizing Solutions by pH

Hi, yes if you want to arrange solutions on their pH, the strong acids will have the lowest pH and the strong bases will have the highest pH so it makes sense to identify these to put them in order. Then of course weak bases will have a lower pH than the strong bases but still higher than the acids ...
by Hana Sigsbee 3B
Sat Dec 12, 2020 5:49 pm
Forum: Administrative Questions and Class Announcements
Topic: other resources
Replies: 5
Views: 63

other resources

Hi everyone, I know Dr. Lavelles has provided us with great review resources this week and throughout the whole quarter but if anyone is still feeling those prefinal nerves like I am I just wanted to give a heads up, The Organic Chemistry Tutor on youtube has some really great, short, concise, video...
by Hana Sigsbee 3B
Sat Dec 12, 2020 5:45 pm
Forum: Administrative Questions and Class Announcements
Topic: FINAL EXAM QUESTIONS
Replies: 36
Views: 366

Re: FINAL EXAM QUESTIONS

Some of the problems will be from the textbook but not all of them.
by Hana Sigsbee 3B
Sat Dec 12, 2020 5:32 pm
Forum: Student Social/Study Group
Topic: Winter Break
Replies: 44
Views: 314

Re: Winter Break

I would suggest maybe a week before class starts up again start reviewing the content of 14A similarly to how you are studying for the final.
by Hana Sigsbee 3B
Sun Dec 06, 2020 9:08 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Determining Oxidation Numbers
Replies: 6
Views: 48

Re: Determining Oxidation Numbers

I remember that we obviously need to charge to be equal to the charge given in the problem so I add all the known charges and then I know the oxidation number of the unknown will make it reach the correct charge from there. For example, if the total charge is known to be +1 and with the given charge...
by Hana Sigsbee 3B
Sun Dec 06, 2020 8:59 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: bookwork 6B.1 #5
Replies: 1
Views: 43

bookwork 6B.1 #5

can someone explain how they got the pH for d, e, and f for this problem, please? Thank you.
by Hana Sigsbee 3B
Sun Dec 06, 2020 8:54 pm
Forum: Administrative Questions and Class Announcements
Topic: 14B and 14BL
Replies: 13
Views: 181

Re: 14B and 14BL

Personally, I am taking 14B and 14BL later on and that is what I have seen other people are doing too but I would have taken them together if I would have had enough units available to do so.
by Hana Sigsbee 3B
Sun Dec 06, 2020 8:52 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: How to find coordination number.
Replies: 10
Views: 70

Re: How to find coordination number.

the coordination number is equal to the number of bonds attached to the central atom
by Hana Sigsbee 3B
Sun Dec 06, 2020 8:51 pm
Forum: Naming
Topic: Sapling 1
Replies: 34
Views: 181

Re: Sapling 1

naming is based on the actual name, not the prefix.
by Hana Sigsbee 3B
Sun Nov 29, 2020 2:01 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Chelate
Replies: 2
Views: 42

Re: Chelate

A chelate is a compound with a ligand that forms a ring of atoms that includes the central metal atom. They include the bidentate, tridentate, and hexadentate ligands which means they are donating 2, 3, or 6 lone pairs. I hope this helped.
by Hana Sigsbee 3B
Sun Nov 29, 2020 1:56 pm
Forum: Administrative Questions and Class Announcements
Topic: grading
Replies: 11
Views: 128

grading

I know in the syllabus it gives us a breakdown of how many point each assignment and each test is worth and says that we have to have a 50% to pass with a -C. Do we know anything else about the grading for this class, like what the break down is for the rest of the letter grades, like what percent w...
by Hana Sigsbee 3B
Sun Nov 29, 2020 1:54 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: polar vs non-polar for molecules
Replies: 2
Views: 16

polar vs non-polar for molecules

To determine if the overall molecule is polar or non-polar it's non-polar if the bonds are non-polar but if the bonds are polar we have to know the molecule's shape and bond angles to see if the polar bonds cancel out and if they do then the molecule if non-polar, correct?
by Hana Sigsbee 3B
Sun Nov 29, 2020 1:52 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: polar vs non-polar
Replies: 7
Views: 62

polar vs non-polar

to determine if the bonds are polar or non-polar we just have to know if the two elements have the same electronegativity or not correct? And if they do have the same it's non-polar and if they're different it's polar?
by Hana Sigsbee 3B
Sun Nov 29, 2020 1:50 pm
Forum: Administrative Questions and Class Announcements
Topic: sapling
Replies: 4
Views: 68

sapling

I noticed that under the grades tab on sapling there are three extra credit sections for the Math Review, Practice Drawing Molecules, and Chemical Equations Training. Are these assignments actually worth extra credit towards our grade or were they just input as that because they weren't actually ass...
by Hana Sigsbee 3B
Sun Nov 22, 2020 4:53 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: different shapes given in notes
Replies: 4
Views: 42

different shapes given in notes

will all the molecules we have to determine the shape of be one of the shapes given to us in our notes, or are there any other shapes we should know about? Also just to double-check the shapes we have been given are: linear, angular, trigonal planar, trigonal pyramidal, t-shaped, tetrahedral, see-sa...
by Hana Sigsbee 3B
Sun Nov 22, 2020 4:43 pm
Forum: Administrative Questions and Class Announcements
Topic: Thanksgiving
Replies: 26
Views: 208

Thanksgiving

Will we still have a lecture on Friday the week of Thanksgiving? I know we're supposed to have that day off but I know on Veterans day we had a lecture.
by Hana Sigsbee 3B
Sun Nov 22, 2020 4:41 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: book problem 2E.5
Replies: 3
Views: 32

book problem 2E.5

2E.5 (a) What is the shape of a ion? (b) What is the expected OClO bond angle?
by Hana Sigsbee 3B
Sun Nov 22, 2020 4:39 pm
Forum: Student Social/Study Group
Topic: Final Jitters
Replies: 250
Views: 36388

Re: Final Jitters

I try to not stay up too late the night before studying, and if anything do maybe a quick review of the topics you feel you need it in the most. The night before I like to meditate or do yoga before bed and make sure I get a good night's sleep. I have my discussion early in the morning but I try to ...
by Hana Sigsbee 3B
Sun Nov 22, 2020 4:36 pm
Forum: Administrative Questions and Class Announcements
Topic: final
Replies: 5
Views: 26

final

do we know yet if the final will be like the midterm and just cover the most recent topics, or will it be cumulative?
by Hana Sigsbee 3B
Sun Nov 22, 2020 4:33 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: shape
Replies: 6
Views: 66

shape

I understand how to determine the shape based on the 3d models but I'm not 100% on how to do so without, could anyone please give me a basic overview on how to do so. I know this is a bit of a silly question, but thank you.
by Hana Sigsbee 3B
Sun Nov 15, 2020 11:35 pm
Forum: Administrative Questions and Class Announcements
Topic: 14B and 14BL
Replies: 6
Views: 46

14B and 14BL

Hi, I am currently trying to plan out my classes for next quarter. I was not sure if it is required to take 14B and 14BL at the same time, because the final for 14BL conflicts with the final for my math class so I would rather not risk that overlap. Does anyone have any recommendations for what I sh...
by Hana Sigsbee 3B
Sun Nov 15, 2020 10:57 pm
Forum: Dipole Moments
Topic: Electric Dipole notation [ENDORSED]
Replies: 1
Views: 34

Electric Dipole notation [ENDORSED]

I know in the textbook we are given the original as well as the modern notation for showing an electric dipole. The textbook says they use the modern notation, is that what we should use as well?
by Hana Sigsbee 3B
Sun Nov 15, 2020 9:38 pm
Forum: Resonance Structures
Topic: bookwork 2C.15
Replies: 2
Views: 24

bookwork 2C.15

"2C.15 Two contributions to the resonance structure are shown below for each species. Determine the formal charge on each atom and then, if possible, identify the Lewis structure of lower energy for each species." How would we tell which lewis structure has lower energy based on the lewis ...
by Hana Sigsbee 3B
Wed Nov 11, 2020 7:12 pm
Forum: Lewis Structures
Topic: homework 2B.3
Replies: 5
Views: 46

homework 2B.3

"2B.3 Draw the Lewis structure of BrF3" for this problem why does the Br in the lewis structure have 10 electrons?
by Hana Sigsbee 3B
Tue Nov 10, 2020 11:28 pm
Forum: Ionic & Covalent Bonds
Topic: 2A.15
Replies: 2
Views: 15

2A.15

"2A.15 Write the most likely charge for the ions formed by each of the following elements: (d) Ga" why will the charge of Ga be +3?
by Hana Sigsbee 3B
Sun Nov 08, 2020 11:45 pm
Forum: Ionic & Covalent Bonds
Topic: resources
Replies: 7
Views: 23

resources

Hi, I am struggling a bit with this section so far. Does anyone know of any good youtube channels or any other resources that I could use to supplement the resources given to us through this class?
by Hana Sigsbee 3B
Sun Nov 08, 2020 11:40 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge Equation
Replies: 16
Views: 74

Re: Formal Charge Equation

L is the number of unpaired electrons and you should be able to find this by just counting the number of unpaired dots in the Lewis Structure model.
by Hana Sigsbee 3B
Sun Nov 08, 2020 11:39 pm
Forum: Octet Exceptions
Topic: specific exceptions
Replies: 3
Views: 11

specific exceptions

are there any exceptions to the octet rule we need to know off the top of our heads or will we be able to tell when we do the configurations if they are an exception all the time?
by Hana Sigsbee 3B
Sun Nov 08, 2020 11:36 pm
Forum: Lewis Structures
Topic: Writing Lewis Structures and Balancing Formal Charge
Replies: 6
Views: 55

Re: Writing Lewis Structures and Balancing Formal Charge

Hi, I believe a good thing to keep in mind for this is that when the formal charge is zero that is when it is most stable so that is the ideal state.
by Hana Sigsbee 3B
Sun Nov 01, 2020 11:40 pm
Forum: Photoelectric Effect
Topic: sapling #22
Replies: 2
Views: 25

sapling #22

You use an electron microscope in which the matter wave associated with the electron beam has a wavelength of 0.0237 nm. What is the kinetic energy of an electron in the beam, expressed in electron volts?
by Hana Sigsbee 3B
Sun Nov 01, 2020 10:38 pm
Forum: DeBroglie Equation
Topic: sapling
Replies: 4
Views: 45

Re: sapling

so on this problem, I got the energy for the photon easily but for some reason, the energy for the electron is giving me trouble. Could someone please walk me through that part a little more thoroughly? I've done it a couple of times now and I'm still not sure what I'm doing wrong.
by Hana Sigsbee 3B
Sun Nov 01, 2020 10:26 pm
Forum: Trends in The Periodic Table
Topic: sapling #23
Replies: 6
Views: 23

sapling #23

The electron affinity of thulium has been measured by a technique known as laser photodetachment electron spectroscopy. In this technique, a gaseous beam of the anions of an element is bombarded with photons from a laser. Electrons from the anion are then ejected and their energies are detected. The...
by Hana Sigsbee 3B
Sun Nov 01, 2020 9:46 pm
Forum: DeBroglie Equation
Topic: sapling
Replies: 4
Views: 45

sapling

The E.coli bacterium is about 2.0 μm long. Suppose you want to study it using photons of that wavelength or electrons having that de Broglie wavelength.
how would I start this problem to find the energy of the photon as well as the energy of the electron?
by Hana Sigsbee 3B
Sun Nov 01, 2020 8:20 pm
Forum: Photoelectric Effect
Topic: sapling problem
Replies: 2
Views: 41

sapling problem

"As you may well know, placing metal objects inside a microwave oven can generate sparks. Two of your friends are arguing over the cause of the sparking, with one stating that the microwaves "herd" electrons into "pointy" areas of the metal object, from which the electrons j...
by Hana Sigsbee 3B
Fri Oct 30, 2020 5:26 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: sapling #6
Replies: 2
Views: 51

sapling #6

"The electron in a hydrogen atom is excited to the n=6 shell and emits electromagnetic radiation when returning to lower energy levels. Determine the number of spectral lines that could appear when this electron returns to the lower energy levels, as well as the wavelength range in nanometers.&...
by Hana Sigsbee 3B
Sun Oct 25, 2020 10:06 pm
Forum: Administrative Questions and Class Announcements
Topic: Constants, Equations, and Periodic Table
Replies: 3
Views: 44

Constants, Equations, and Periodic Table

For the midterm, should we be using the printable lists of constants and equations off of Dr. Lavelle's website or should we use the one he has linked to buy through Amazon.
by Hana Sigsbee 3B
Sun Oct 25, 2020 9:56 pm
Forum: Properties of Light
Topic: Textbook Questions and Midterm
Replies: 6
Views: 61

Re: Textbook Questions and Midterm

Dr. Lavelle's email stated this midterm only covers up to last Wednesday's lecture, homework 1D, and up to sapling homework problem 19. He also said the "Review of Chemical and Physical Principles" as well as up to the tenth bullet point of the "Quantum World" outline is the cont...
by Hana Sigsbee 3B
Sun Oct 25, 2020 9:49 pm
Forum: DeBroglie Equation
Topic: Derivation of Equations on Midterm?
Replies: 17
Views: 112

Re: Derivation of Equations on Midterm?

I believe we just have to have an understanding of how the equations were derived but I do not believe we will be required to actually show how they were derived.
by Hana Sigsbee 3B
Sun Oct 25, 2020 9:39 pm
Forum: Significant Figures
Topic: Sig Figs and Constants on Exams
Replies: 9
Views: 109

Re: Sig Figs and Constants on Exams

Hi, I have noticed that in lectures and practice problems the constants are generally rounded but he has said to keep all values and not round until the end number to ensure you get the correct value and number of sig figs so I would not round at first just to be safe.
by Hana Sigsbee 3B
Sun Oct 25, 2020 9:34 pm
Forum: SI Units, Unit Conversions
Topic: conversion factors
Replies: 8
Views: 62

conversion factors

are there any specific conversion factors we are expected to know for the midterm that are not basic common knowledge ones?
by Hana Sigsbee 3B
Sun Oct 18, 2020 11:36 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Book Problem 1E.7
Replies: 1
Views: 24

Book Problem 1E.7

For 1E.7 in the textbook, how would we "Determine whether each of the following electron configurations represents the ground state or an excited state of the atom given." based on the model that was given?
by Hana Sigsbee 3B
Sun Oct 18, 2020 11:33 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configurations that dont follow the pattern
Replies: 3
Views: 26

Electron Configurations that dont follow the pattern

when predicting an electron configuration, how would we know if a certain element will follow the pattern or not?
by Hana Sigsbee 3B
Thu Oct 15, 2020 11:48 pm
Forum: DeBroglie Equation
Topic: book problem 1B.15
Replies: 1
Views: 26

book problem 1B.15

1B.15 The velocity of an electron that is emitted from a metallic surface by a photon is 3.6 × 10 3 km ⋅ s − 1 . (a) What is the wavelength of the ejected electron? (b) No electrons are emitted from the surface of the metal until the frequency of the radiation reaches 2.50 × 10 16 Hz . How much ener...
by Hana Sigsbee 3B
Thu Oct 15, 2020 11:16 pm
Forum: Photoelectric Effect
Topic: 1B.9
Replies: 1
Views: 42

1B.9

"1B.9 A lamp rated at 32 W ( 1 W = 1 J ⋅ s − 1 ) emits violet light of wavelength 420 nm. How many photons of violet light can the lamp generate in 2.0 s? How many moles of photons are emitted in that time interval?" would anyone be able to give me a step by step explanation on how to do t...
by Hana Sigsbee 3B
Mon Oct 12, 2020 9:24 pm
Forum: Photoelectric Effect
Topic: Photoelectric Effect original purpose
Replies: 6
Views: 35

Re: Photoelectric Effect original purpose

thank you, that's what I thought just wanted to double-check.
by Hana Sigsbee 3B
Mon Oct 12, 2020 8:47 pm
Forum: Photoelectric Effect
Topic: Photoelectric Effect original purpose
Replies: 6
Views: 35

Photoelectric Effect original purpose

Hi, I was not super clear on this after the lecture but could anyone please clarify for me what the photoelectric experiment was originally designed to do?
by Hana Sigsbee 3B
Sat Oct 10, 2020 5:20 pm
Forum: Properties of Light
Topic: Electromagnetic Spectrum
Replies: 7
Views: 55

Re: Electromagnetic Spectrum

Red and Violet do have different wavelengths. Red is 700nm whereas violent is 420nm. As you move down the electromagnetic spectrum from radio waves toward x-rays the wavelengths shorten and the energy increases.
by Hana Sigsbee 3B
Sat Oct 10, 2020 5:16 pm
Forum: SI Units, Unit Conversions
Topic: Angstrom vs. pm +Solutions Manual
Replies: 4
Views: 67

Re: Solutions Manual

Hi, I also found that on sapling under "resources" there is a pdf labeled "Atkins 7e SSM" that has the solutions to the book problems as well. Also if you want to check your work I found that if you copy and paste the question just in google the questions likely already been aske...
by Hana Sigsbee 3B
Sat Oct 10, 2020 5:11 pm
Forum: Empirical & Molecular Formulas
Topic: Sapling Hw 1 #10
Replies: 5
Views: 47

Re: Sapling Hw 1 #10

Hi, I found the best way to solve this problem was to look up the formulas for each component of the reaction and go from there. When I looked these up I found that 2-butanone was C4H8O, 1-bromopropane was C3H7Br, and 3-methyl-3-hexanol was C7H16O. From there I used conversion factors to find the mo...
by Hana Sigsbee 3B
Wed Oct 07, 2020 1:27 pm
Forum: Molarity, Solutions, Dilutions
Topic: G. 25 Fundamentals book problem
Replies: 3
Views: 76

G. 25 Fundamentals book problem

Hi, I was having some trouble with this problem from section G of the Fundamentals. I would love some help figuring out how to start the problem. Thank you! "G.25 Practitioners of the branch of alternative medicine known as homeopathy claim that very dilute solutions of substances can have an e...
by Hana Sigsbee 3B
Wed Oct 07, 2020 1:19 pm
Forum: Limiting Reactant Calculations
Topic: Actual and Theoretical yields
Replies: 14
Views: 145

Re: Actual and Theoretical yields

Hi, I do not believe there are any instances in which the theoretical yield and actual yield will be equal. Actual yield was defined in an earlier post on here as, "...not equal to the theoretical yield because of side reactions that occur as well as impurities in the container that might hinde...

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