Search found 113 matches
- Thu Feb 25, 2021 1:08 pm
- Forum: Administrative Questions and Class Announcements
- Topic: 14C, 14CL closed after first enrollment pass
- Replies: 7
- Views: 601
Re: 14C, 14CL closed after first enrollment pass
I'd recommend getting the Coursicle app and tracking when people drop the class so you can enroll in it. I haven't used it but I have heard that people who have used it have been able to snag the class they wanted.
- Thu Feb 25, 2021 1:01 pm
- Forum: Student Social/Study Group
- Topic: Classes for next quarter?
- Replies: 165
- Views: 13012
Re: Classes for next quarter?
I am taking Chem 14BL, LS30B, and 2 GEs!
- Thu Feb 25, 2021 12:59 pm
- Forum: Student Social/Study Group
- Topic: Exercising Our Minds and Bodies
- Replies: 120
- Views: 15153
Re: Exercising Our Minds and Bodies
I love going swimming, really clears the mind and it's nice to go outside
- Tue Feb 23, 2021 7:28 am
- Forum: Student Social/Study Group
- Topic: Fave food
- Replies: 266
- Views: 28426
Re: Fave food
I love trader joes and all of their snacks. Personally I am craving the trader joes cassava chips with the trader joes romesco sauce.
- Tue Feb 23, 2021 7:25 am
- Forum: Student Social/Study Group
- Topic: Chem 14B Final
- Replies: 86
- Views: 5080
Re: Chem 14B Final
Doing all the textbook problems and understanding them. Also for 14A the TAs had review sessions, I would assume they are doing review session this quarter too and I would recommend going to them.
- Sun Feb 14, 2021 9:05 am
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Sapling #5 week 5 and 6
- Replies: 13
- Views: 596
Re: Sapling #5 week 5 and 6
SophiaNguyen_2L wrote:Hi! All these answers are super helpful, so thank you all. When calculating the mols of gas in the PV=nRT equation, which temperature would you use when they give you and initial and final temperature? Thank you!
You want to use the initial temperature when calculating the mols of gas
- Sat Feb 13, 2021 12:30 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Sapling HW Week 5/6 Question #18
- Replies: 3
- Views: 934
Re: Sapling HW Week 5/6 Question #18
For 3NO2(g)+H2O(l)↽−−⇀2HNO3(aq)+NO(g) I got K=1.7×10^9 1) First we want to find the standard Gibbs free energy ΔGr =[2ΔGf(HNO3) + ΔGf(NO)] − [3ΔGf(N2) + ΔGf(H2O)] - then plug in the given values ΔGr = −52.75kJ/mol -then convert to J ΔGr = −5.275×10^4J/mol 2) Next we want to find the equilibrium cons...
- Sat Feb 13, 2021 12:19 pm
- Forum: Phase Changes & Related Calculations
- Topic: week 5/6 sapling assignment
- Replies: 2
- Views: 222
Re: week 5/6 sapling assignment
ΔS > 0 -- Solid to liquid, liquid to gas, and solid to gas have positive changes in entropy ΔS < 0 -- Liquid to solid, gas to liquid, and gas to solid all have negative changes in entropy ΔH > 0 -- Solid to liquid, liquid to gas, and solid to gas all have positive changes in enthalpy ΔH < 0 -- Liqu...
- Sat Feb 13, 2021 12:14 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Sapling 3 Week 5/6
- Replies: 2
- Views: 198
Re: Sapling 3 Week 5/6
You would use this equation:
ΔS = qrev/T
Then just plug in the values you were given (remember to convert seconds to hours and Celsius to Kelvin):
ΔS = (81.0 J/sec * 60 sec/min * 60 min/hr) / (25.3+273.15)K = 977
ΔS = qrev/T
Then just plug in the values you were given (remember to convert seconds to hours and Celsius to Kelvin):
ΔS = (81.0 J/sec * 60 sec/min * 60 min/hr) / (25.3+273.15)K = 977
- Fri Feb 12, 2021 10:08 am
- Forum: Student Social/Study Group
- Topic: Classes for next quarter?
- Replies: 165
- Views: 13012
Re: Classes for next quarter?
I'm taking Chem 14BL, LS30B, a Writing 3 class, and maybe a fiat lux!
- Fri Feb 12, 2021 9:55 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Is it necessary to memorize Cp,m or Cv,m values? [ENDORSED]
- Replies: 26
- Views: 1172
Re: Is it necessary to memorize Cp,m or Cv,m values? [ENDORSED]
Hi, on the constants and formulas sheet (https://lavelle.chem.ucla.edu/wp-conten ... ations.pdf) we are given Ideal gas Cp, Ideal gas Cv, Cp of water, and Cp of ice.
- Sun Feb 07, 2021 5:16 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Sapling 17
- Replies: 2
- Views: 332
Re: Sapling 17
You would use this equation: E = q +w, and rearrange to solve for q: q = E - w. Then plug in your values. w=-346 J because work is done by the system, and E = + 7545 J since there was an increase in internal energy. q = 7545 J - (-346J) q = 7891 After finding q you would use it to find specific heat...
- Sun Feb 07, 2021 3:55 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: hw problem #9
- Replies: 3
- Views: 236
Re: hw problem #9
So we can set the heat gained by the cold water to the heat lost by the hot water m(cold water) * c * ΔT(cold water)= -m(hot water) * c * ΔT(hot water) and from here we can just plug in the values. *remember that c = 4.184J/gC & ΔT= Tfinal - Tinital (270.0g) * (4.184J/gC ) * (Tfinal - 25.00C) = ...
- Sun Feb 07, 2021 3:50 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Sapling wk 3/4 #17
- Replies: 5
- Views: 539
Re: Sapling wk 3/4 #17
You would use this equation: E = q +w, and rearrange to solve for q: q = E - w. Then plug in your values. w=-346 J because work is done by the system, and E = +6055J since there was an increase in internal energy. q = 6055J - (-346J) q = 6401 After finding q you would use it to find specific heat us...
- Sat Feb 06, 2021 2:28 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Week 3/4 Sapling #9
- Replies: 13
- Views: 667
Re: Week 3/4 Sapling #9
So we can set the heat gained by the cold water to the heat lost by the hot water m(cold water) * c * ΔT(cold water)= -m(hot water) * c * ΔT(hot water) and from here we can just plug in the values. *remember that c = 4.184J/gC & ΔT= Tfinal - Tinital (230.0g) * (4.184J/gC ) * (Tfinal - 25.00C) =...
- Tue Feb 02, 2021 1:50 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Week 3/4 Sapling #9
- Replies: 13
- Views: 667
Re: Week 3/4 Sapling #9
So we can set the heat gained by the cold water to the heat lost by the hot water m(cold water) * c * ΔT(cold water)= -m(hot water) * c * ΔT(hot water) and from here we can just plug in the values. *remember that c = 4.184J/gC & ΔT= Tfinal - Tinital (230.0g) * (4.184J/gC ) * (Tfinal - 25.00C) = ...
- Mon Feb 01, 2021 9:03 am
- Forum: Phase Changes & Related Calculations
- Topic: endothermic/exothermic
- Replies: 43
- Views: 4328
Re: endothermic/exothermic
And then when it comes to reactions you can look at the bond strengths to figure out if the reaction is endothermic or exothermic. (This is asked in Sapling Week 3/4, questions 4.) We know that an endothermic reaction has a large energy requirement, with a small energy release. So for an endothermic...
- Mon Feb 01, 2021 8:25 am
- Forum: Phase Changes & Related Calculations
- Topic: Sapling Week 3/4 Q4
- Replies: 10
- Views: 488
Re: Sapling Week 3/4 Q4
An endothermic reaction has a large energy requirement, with a small energy release. So for an endothermic reaction it would have stronger reactant bonds and weaker product bonds. For example, for a reaction: B2+C2⟶2BC, B–B and C–C bonds are stronger than B–C bonds so it would be endothermic. An exo...
- Mon Feb 01, 2021 8:23 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Sapling #4
- Replies: 7
- Views: 439
Re: Sapling #4
Endothermic: large energy requirement, with a small energy release. So for an endothermic reaction it would have stronger reactant bonds and weaker product bonds. For example, for a reaction: B2+C2⟶2BC, B–B and C–C bonds are stronger than B–C bonds so it would be endothermic. Exothermic: small energ...
- Mon Feb 01, 2021 7:52 am
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Sapling 11 week 3/4
- Replies: 2
- Views: 219
Re: Sapling 11 week 3/4
Yes so to do this problem you would use the equation that gives the heat lost or absorbed q=c*m*ΔT and we can state that qwater=−qmetal, so you can set up the equation as m(water) * c(water) * ΔT(water)= −m(metal) * c(metal) * ΔT(metal) **also remember that ΔT = (Tfinal - Tinitial) using what you we...
- Mon Feb 01, 2021 7:38 am
- Forum: Student Social/Study Group
- Topic: Favorite Music
- Replies: 113
- Views: 9776
Re: Favorite Music
My current favorite song is Everyday by ASAP Rocky & Rob Stewart. I would say my current go to artists are Mac Miller, Peach Pit, Roy Blair, & Steve Lacy. For me the best way to discover new music is my Spotify discover weekly playlist and also Tiktok!
- Mon Jan 25, 2021 10:42 am
- Forum: General Science Questions
- Topic: Rusty on High School Chem [ENDORSED]
- Replies: 347
- Views: 416031
Re: Rusty on High School Chem [ENDORSED]
Does anyone have a good/ established structure they would want to share when they would study for Chem 14B? I just want to make sure I'm knocking everything to prepare me well for the exams. I really recommend the textbook and sapling problems. Based on Chem14A it seems like Lavelle tends to pull q...
- Sun Jan 24, 2021 5:14 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Textbook Problems Not Listed in Syllabus
- Replies: 3
- Views: 243
Re: Textbook Problems Not Listed in Syllabus
I would just focus on the questions assigned. Lavelle tends to pull from the assigned textbook problems when making his exams!
- Sun Jan 24, 2021 5:10 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Week 2 Sapling #2
- Replies: 9
- Views: 379
Re: Week 2 Sapling #2
I'm not sure if that equation is correct, but the way I did it was I got the equation (0.154-x)/x^2 = 0.0032. Then, I rearranged the equation so that it becomes a quadratic. It should look like this: 0.032x^2+x-0.154. Then, you just use the quadratic to get the x value. And you must use the most re...
- Sun Jan 24, 2021 5:05 pm
- Forum: Administrative Questions and Class Announcements
- Topic: midterm
- Replies: 11
- Views: 525
Re: midterm
Going off of what Hana said the zoom is on an external device. Most people used their phones to show their workspace and took the exam on their laptops.
- Sun Jan 24, 2021 5:02 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm 1 Zoom
- Replies: 8
- Views: 387
Re: Midterm 1 Zoom
Last time we were sent links prior to our exams. I think that is how it is going to be this time as well!
- Sat Jan 23, 2021 11:30 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: sapling 2 week 2
- Replies: 7
- Views: 453
Re: sapling 2 week 2
You set up the equation like ka = [H+][A−]/[HA] ka = x^2/(initial moles) - x then your equation will be x^2 + 0.00459x - (0.00459*.14) x^2+0.00459x-6.426E-4 Your roots will be x = 0.02315823, −0.02774823 The equation for percent ionization is ([H+]equilibrium/[HA]initial) * 100. You will want to use...
- Wed Jan 20, 2021 1:23 pm
- Forum: Student Social/Study Group
- Topic: Calculators
- Replies: 52
- Views: 3064
Re: Calculators
Yep, calculators are allowed for all exams!
- Mon Jan 18, 2021 8:21 pm
- Forum: General Science Questions
- Topic: Rusty on High School Chem [ENDORSED]
- Replies: 347
- Views: 416031
Re: Rusty on High School Chem [ENDORSED]
Does anyone have a good/ established structure they would want to share when they would study for Chem 14B? I just want to make sure I'm knocking everything to prepare me well for the exams. I really recommend the textbook and sapling problems. Based on Chem14A it seems like Lavelle tends to pull q...
- Mon Jan 18, 2021 8:07 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: midterms [ENDORSED]
- Replies: 10
- Views: 643
Re: midterms [ENDORSED]
No class that day due to midterm. :-) Hello :) Are there any accommodations in place for international students for the midterm like there is for the final? Thanks in advance! Oh! It seems like Lavelle will make an announcement about this soon https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=160...
- Mon Jan 18, 2021 8:05 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Seeing replies on Chemistry Community
- Replies: 10
- Views: 515
Re: Seeing replies on Chemistry Community
You can check the box under options "Notify me when a reply is posted" if you want to get replies. This box is right under the submit button.
- Mon Jan 18, 2021 8:03 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: midterms [ENDORSED]
- Replies: 10
- Views: 643
Re: midterms [ENDORSED]
No class that day due to midterm. :-) Hello :) Are there any accommodations in place for international students for the midterm like there is for the final? Thanks in advance! It seems like there is an alternative time for the final exam but not for the midterms (Sunday March 14, 8am-9:30am). Thoug...
- Mon Jan 18, 2021 7:59 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Chem Community and Sapling Grades
- Replies: 25
- Views: 1055
Re: Chem Community and Sapling Grades
Agree with what everyone said above. I would recommend to wait a couple of days for the CCLE grades section to update since the TAs have to enter the grades and it sometimes takes a couple of days before everything is added in.
- Sat Jan 16, 2021 8:12 pm
- Forum: Student Social/Study Group
- Topic: Best Workshops
- Replies: 8
- Views: 289
Re: Best Workshops
You can also access the worksheets from this link if you want more practice and can't make it to the workshops. https://drive.google.com/drive/folders/ ... ODsKNCF5fe
- Sat Jan 16, 2021 8:11 pm
- Forum: General Science Questions
- Topic: step up sessions
- Replies: 16
- Views: 890
Re: step up sessions
There is also a link with all worksheets if you missed the session but still want the practice. https://drive.google.com/drive/folders/1-iUlSUXyOWLHC5chqYRLC2ODsKNCF5fe are these from each step session or is it just one ? these are from a few different step up sessions (it might be all). they have ...
- Sun Jan 10, 2021 8:21 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Using "ICE"
- Replies: 9
- Views: 402
Re: Using "ICE"
When using ICE tables make sure your values are concentrations, your units should be moles/liters.
c= n/V
c= n/V
- Sun Jan 10, 2021 8:09 pm
- Forum: General Science Questions
- Topic: midterm/final
- Replies: 12
- Views: 611
Re: midterm/final
Sorry if this has already been addressed somewhere, but are the midterms/finals only during lecture times, or can they be taken at alternate times if you are in a different timezone? I took 14A over summer so I'm not sure how it works. Thank you! Our exams are during the Friday lecture timeslot, bu...
- Sun Jan 10, 2021 8:05 pm
- Forum: General Science Questions
- Topic: step up sessions
- Replies: 16
- Views: 890
Re: step up sessions
There is also a link with all worksheets if you missed the session but still want the practice.
https://drive.google.com/drive/folders/1-iUlSUXyOWLHC5chqYRLC2ODsKNCF5fe
https://drive.google.com/drive/folders/1-iUlSUXyOWLHC5chqYRLC2ODsKNCF5fe
- Sun Jan 10, 2021 8:03 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Water
- Replies: 28
- Views: 915
Re: Water
In general, don't include anything that is a solid or liquid or solvent in your calculations.
- Tue Jan 05, 2021 7:54 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Equilibrium is shifted to the right/left
- Replies: 9
- Views: 920
Equilibrium is shifted to the right/left
Hi, what does it mean when the equilibrium is shifted to the right/left? How would that reflect in K?
This is question 31 & 32 on the 1A module.
This is question 31 & 32 on the 1A module.
- Wed Dec 16, 2020 9:01 am
- Forum: Student Social/Study Group
- Topic: grade worries
- Replies: 119
- Views: 14509
Re: grade worries
I am also starting to worry about my grade. I also don't like how there isn't anywhere we can check what grade we have in the class currently. I am not used to that. There is a way to check your grade! Go to the grades section of the CCLE site. There you will see all the points you got. Add up all ...
- Tue Dec 15, 2020 4:34 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Saying Thank You to Dr. Lavelle
- Replies: 490
- Views: 512904
Re: Saying Thank You to Dr. Lavelle
THANK YOU DR. LAVELLE!!! I am looking forward to next quarter: Chem14B. :D
- Tue Dec 15, 2020 4:32 pm
- Forum: Student Social/Study Group
- Topic: Winter Break Plans
- Replies: 45
- Views: 1922
Winter Break Plans
What are you guys doing over winter break? Also do you have any good book or movie recommendations?
I am going to be road tripping down the Pacfic Coastal Highway with my family in an RV (social distancing at its finest). I am super excited to visit a bunch of beaches and escape my house. :)
I am going to be road tripping down the Pacfic Coastal Highway with my family in an RV (social distancing at its finest). I am super excited to visit a bunch of beaches and escape my house. :)
- Tue Dec 15, 2020 4:28 pm
- Forum: Student Social/Study Group
- Topic: Staying Motivated
- Replies: 38
- Views: 1568
Re: Staying Motivated
This was my first UCLA quarter and it was crazy to me how fast the quarter went and how much work there was. Honestly, I know that I could have done better and I want to set up a plan for next quarter (and the quarters to come) so I will stay on track. I think the main thing with motivation is knowi...
- Tue Dec 15, 2020 3:31 pm
- Forum: Student Social/Study Group
- Topic: Changing Study Habits
- Replies: 35
- Views: 1279
Re: Changing Study Habits
Like you I plan on doing the textbook problems earlier and going to UA sessions etc. I will also utilize chemistry community more and use the worksheets that UA's and TA's post on here. Also we get points for the posts we make in the next two days because chemistry community was down for the past t...
- Tue Dec 15, 2020 10:11 am
- Forum: Conjugate Acids & Bases
- Topic: Sapling 14
- Replies: 6
- Views: 345
Re: Sapling 14
Yes you are correct, it would be neutral!
- Tue Dec 15, 2020 10:09 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2978124
Re: Post All Chemistry Jokes Here
I asked my brother he had some sodium hypobromite, but he said NaBrO.
- Tue Dec 15, 2020 9:58 am
- Forum: Student Social/Study Group
- Topic: Words of encouragement
- Replies: 14
- Views: 724
Re: Words of encouragement
Good luck on finals and hope everyone has a great and restful winter break !
- Tue Dec 15, 2020 9:57 am
- Forum: Student Social/Study Group
- Topic: Final Exam
- Replies: 49
- Views: 2437
Re: Final Exam
I was def rushed so I am glad that we were able to get 10 points back.
- Tue Dec 15, 2020 9:54 am
- Forum: Student Social/Study Group
- Topic: Changing Study Habits
- Replies: 35
- Views: 1279
Changing Study Habits
I am reflecting on this quarter and my study habits to see what went well and how I could do better. For Chem 14B I plan to focus a lot more energy on the textbook problems and gaining a solid understanding of each problem. I also hope to attend more office hours and UA sessions. What are some thing...
- Tue Dec 15, 2020 9:50 am
- Forum: Student Social/Study Group
- Topic: How are you?
- Replies: 154
- Views: 12343
Re: How are you?
I am so relieved that we got through this chem quarter! I am also really happy that we are getting 10 points extra on the final. Just a few more finals to go for me and then winter break!
- Sat Dec 12, 2020 9:49 am
- Forum: Hybridization
- Topic: Textbook Question 2.57
- Replies: 2
- Views: 276
Re: Textbook Question 2.57
I also got the same thing! I was looking for the answers too :)
- Wed Dec 09, 2020 9:12 pm
- Forum: General Science Questions
- Topic: midterm 2 answers
- Replies: 30
- Views: 1985
Re: midterm 2 answers
As everyone said above you can go to your TA's office hours or make an appointment with them and they will walk you through what you got wrong (but they do not show you the exam/share their screen they just talk it out). I highly recommend this as it was helpful for me to know what I should review -...
- Wed Dec 09, 2020 9:10 pm
- Forum: Student Social/Study Group
- Topic: Review Session
- Replies: 11
- Views: 604
Re: Review Session
The Friday review session will be during "class" so that means it will be posted where all our other lectures are on Friday.
- Wed Dec 09, 2020 9:07 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Expected vs. Predicted bond angle
- Replies: 1
- Views: 216
Expected vs. Predicted bond angle
When asked for the expected bond angle do we say less than [angle] and when asked for the predicted bond angle do we just say [angle]? For example when asked for the predicted bond angle for a linear shape the answer would be 180 and then when asked for the expect bond angle for a linear shape the a...
- Thu Dec 03, 2020 7:08 am
- Forum: Naming
- Topic: what does (en) mean?
- Replies: 23
- Views: 10030
Re: what does (en) mean?
I think it is helpful to know that en/ethylenediamine has no charge, it is neutral.
- Wed Dec 02, 2020 12:34 pm
- Forum: Student Social/Study Group
- Topic: Calculating grade
- Replies: 24
- Views: 1430
Re: Calculating grade
Breakdown of the grade: Sapling - 50 pts Chemistry Community - 50 pts Midterm 1 - 110 pts Midterm 2 - 110 pts Final - 180 pts Total 500 pts You can calculate your grade (assume what you will get from sapling & chem community) and estimate you final grade. You can also use this to figure out your...
- Wed Dec 02, 2020 12:32 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Weekly discussion points
- Replies: 13
- Views: 694
Re: Weekly discussion points
To get full credit you have to have at least 5 points each week. You cannot skip weeks and just get more points the next week, the grading scale is based on each week.
- Wed Dec 02, 2020 12:30 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Questions About Final
- Replies: 7
- Views: 465
Re: Questions About Final
Excerpt from this doc (https://lavelle.chem.ucla.edu/wp-content/supporting-files/Chem14A/Final_Review_Sessions_14A.pdf): Final is same format as midterms. All tests are proctored and closed book. CCLE link will be under folder called FINAL. Final is 90 minutes with 30 questions each 6 points (180 po...
- Wed Dec 02, 2020 12:28 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm 1 and 2 Review
- Replies: 8
- Views: 490
Re: Midterm 1 and 2 Review
As everyone said above you can go to your TA's office hours and they will walk you through what you got wrong (but they do not show you the exam/share their screen they just talk it out). I highly recommend this as it was helpful for me to know what I should review -- I thought I understood certain ...
- Wed Dec 02, 2020 12:25 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: How to find Oxidation Numbers
- Replies: 4
- Views: 278
Re: How to find Oxidation Numbers
I think we are supposed to memorize them. Here is a list of them all with the charges https://sites.google.com/site/chempendix/ligands
- Wed Dec 02, 2020 12:24 pm
- Forum: Administrative Questions and Class Announcements
- Topic: 14B vs 14A
- Replies: 12
- Views: 628
Re: 14B vs 14A
As for the format of the class it is still up in the air according to these posts by Lavelle:
1) viewtopic.php?t=67049
2) viewtopic.php?t=67067
1) viewtopic.php?t=67049
2) viewtopic.php?t=67067
- Wed Dec 02, 2020 12:21 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Charges on Metals
- Replies: 3
- Views: 255
Charges on Metals
This might be a dumb question but how do you know the charges of the atom on the outside of the brackets? For example:
Na[Ag(CN)2], here Na has a +1 charge. How do we know that and how can we figure out other atom charges?
Na[Ag(CN)2], here Na has a +1 charge. How do we know that and how can we figure out other atom charges?
- Mon Nov 30, 2020 8:16 am
- Forum: Resonance Structures
- Topic: finding resonance structures
- Replies: 5
- Views: 450
Re: finding resonance structures
I struggle with this too! Sophia gave a lot of great tips. I think it's a lot of playing around with moving things and seeing what could work: changing double bonds to single bonds with electron pairs. Unfortunately there is no set steps on how to find resonance, but practice will help you get faster.
- Sun Nov 29, 2020 12:02 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final
- Replies: 15
- Views: 547
Re: Final
Since there is so much more time, do you guys think he will make the test harder but keep the same amount of questions or make the test the same but add a lot more questions? I think the test will have more questions. Since he gives up ~5 minutes per question and the final is 90 minutes then maybe ...
- Sun Nov 29, 2020 11:43 am
- Forum: Administrative Questions and Class Announcements
- Topic: Final
- Replies: 15
- Views: 547
Re: Final
Based on the website the test will be on December 13th from 11:30 to 1pm - that is a Sunday. I am guessing that it will be a similar setting like our midterms.
- Sun Nov 29, 2020 11:40 am
- Forum: Student Social/Study Group
- Topic: Final Study
- Replies: 32
- Views: 1367
Re: Final Study
I am going to start studying for the final this coming week -- week 9. I am just going to start by re doing the textbook problems and making a cheatsheet/guide on how to do all types of problems so it will be easy to remember how to tackle problems. I also am going to be attending UA sessions throug...
- Sun Nov 29, 2020 11:34 am
- Forum: Student Social/Study Group
- Topic: Week 8/9 Thoughts/Worries
- Replies: 66
- Views: 3165
Re: Week 8/9 Thoughts/Worries
I feel like overall it has been going well. I like with this class there are a lot of ways to practice what we are learning -- UA sessions, textbook problems, chem community, and sapling. I started a little shaky on the first exam but I improved on this recent exam as I understand how to study bette...
- Sun Nov 29, 2020 11:27 am
- Forum: Student Social/Study Group
- Topic: Final Exam Tips
- Replies: 24
- Views: 898
Re: Final Exam Tips
I am going to redo the textbook problems since he pulls his questions from there. I am also going to read through the sapling questions and answers. I also have heard that the UAs give out practice exams and they might be giving out practice final exams.
- Sun Nov 29, 2020 11:15 am
- Forum: Administrative Questions and Class Announcements
- Topic: 14B
- Replies: 11
- Views: 675
Re: 14B
Check these posts by Lavelle out for all your questions about 14B:
- viewtopic.php?t=67049
- viewtopic.php?t=67067
- https://lavelle.chem.ucla.edu/wp-conten ... stions.pdf
- viewtopic.php?t=67049
- viewtopic.php?t=67067
- https://lavelle.chem.ucla.edu/wp-conten ... stions.pdf
- Fri Nov 20, 2020 8:27 am
- Forum: Bond Lengths & Energies
- Topic: Textbook Question 3F.15
- Replies: 8
- Views: 466
Re: Textbook Question 3F.15
AsF3 would have a higher boiling point than AsF5 because it is a polar molecule that has Dipole-Dipole and LDF. AsF5 only experiences LDF because all of the Fluorines are pulling it equally. Could you please walk me through how you realized that AsF5 is a polar molecule? Hey! Sorry AsF3 is the pola...
- Thu Nov 19, 2020 7:14 pm
- Forum: Properties & Structures of Inorganic & Organic Bases
- Topic: Inorganic and Organic
- Replies: 7
- Views: 706
Re: Inorganic and Organic
Organic compounds always contain carbon while inorganic compounds contain metal and other elements.
I'm working through the textbook problems now and will reply if I find any about this topic.
I'm working through the textbook problems now and will reply if I find any about this topic.
- Thu Nov 19, 2020 6:23 pm
- Forum: Bond Lengths & Energies
- Topic: Textbook Question 3F.15
- Replies: 8
- Views: 466
Re: Textbook Question 3F.15
Selena Quispe 2G wrote:AsF3 would have a higher boiling point than AsF5 because it is a polar molecule that has Dipole-Dipole and LDF. AsF5 only experiences LDF because all of the Fluorines are pulling it equally.
Could you please walk me through how you realized that AsF5 is a polar molecule?
- Thu Nov 19, 2020 6:20 pm
- Forum: Student Social/Study Group
- Topic: grade worries
- Replies: 119
- Views: 14509
Re: grade worries
I know we are all worried, but we got this!! Just a few more weeks.
- Thu Nov 19, 2020 6:18 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Quantum number ms
- Replies: 3
- Views: 234
Re: Quantum number ms
Thanks for clearing that up guys!
- Thu Nov 19, 2020 6:17 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: 3d fills before or after 4s?
- Replies: 7
- Views: 515
Re: 3d fills before or after 4s?
Oh ahhhh that makes more sense, thank you guys!
- Thu Nov 19, 2020 6:17 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Polarizability vs Polarizing Power in anions/cations & bonding
- Replies: 10
- Views: 505
Re: Polarizability vs Polarizing Power in anions/cations & bonding
To add on in terms of periodic trends Polarizability decreases as it goes across a period and increases as it goes down a group. This is because the greater the number of electrons, the less control the nuclear charge has on charge distribution, and thus the increased polarizability of the atom. As ...
- Thu Nov 19, 2020 2:00 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: 3d fills before or after 4s?
- Replies: 7
- Views: 515
3d fills before or after 4s?
For textbook problem 2A.5 it asks to give the ground-state electron configuration expected for Cu+ I thought the answer would be [Ar]3d^8 4s^2 since 4s has a lower energy than 3d and would fill up first. However the answer is [Ar]3d^10. Why doesn't the 4s fill up first? What is the order of the elec...
- Mon Nov 16, 2020 2:07 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Quantum number ms
- Replies: 3
- Views: 234
Quantum number ms
How do you know if the quantum number ms (spin) is +½ or -½? Is the purpose of knowing that ms can be +½ or -½ only used for know that the arrows in the electron configuration have opposite spins?
- Mon Nov 16, 2020 1:21 pm
- Forum: Administrative Questions and Class Announcements
- Topic: 14B Next Quarter
- Replies: 8
- Views: 345
Re: 14B Next Quarter
Lavelle is accepting everyone off of the waitlist. Lavelle is not sure if the class will have asynchronous lectures next quarter. Check these posts by Lavelle out: - https://lavelle.chem.ucla.edu/forum/viewtopic.php?t=67049 - https://lavelle.chem.ucla.edu/forum/viewtopic.php?t=67067 - https://lavell...
- Mon Nov 16, 2020 1:11 pm
- Forum: Dipole Moments
- Topic: Bonds on MT2?
- Replies: 1
- Views: 90
Bonds on MT2?
What are the different type of bonds do we need to know for the MT2 and how do they differ?
- Mon Nov 16, 2020 1:08 pm
- Forum: Student Social/Study Group
- Topic: Exercising Our Minds and Bodies
- Replies: 120
- Views: 15153
Re: Exercising Our Minds and Bodies
I enjoy swimming in the ocean, going on hikes, and not going to lie TikTok dances are a workout!
- Mon Nov 16, 2020 1:06 pm
- Forum: Dipole Moments
- Topic: Dipole moment vs dipole bond
- Replies: 5
- Views: 407
Re: Dipole moment vs dipole bond
I think you are asking the difference between bond dipole/dipole moments formula and dipole-dipole forces. Dipole-Dipole Forces are intermolecular attractions between two molecules. They are the weakest bonds and all polar covalent compounds have them The dipole moments formula measure the polarity ...
- Mon Nov 16, 2020 12:59 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Polarizability
- Replies: 3
- Views: 177
Re: Polarizability
To add on even more, polarizability tends to decrease from left to right since the atomic radius and the number of electrons decreases.
- Mon Nov 16, 2020 12:57 pm
- Forum: Student Social/Study Group
- Topic: Midterm 2 content
- Replies: 20
- Views: 739
Re: Midterm 2 content
The only equation that I think we will need to know is Formal Charge: Formal Charge of Atom = V - L - B/2 - V - Valence Electrons of Atom - found using the periodic table of elements - L # of Lone Electrons on Atom - these are the lone individual electrons - B/2 # bonded electrons with Atom/2 - each...
- Mon Nov 16, 2020 12:53 pm
- Forum: Student Social/Study Group
- Topic: Test Anxiety
- Replies: 62
- Views: 2964
Re: Test Anxiety
Deep breathes throughout the whole test. Also remember that you have prepared, you just have to show your learning here. Take it slow and read the questions veryyy carefully.
- Mon Nov 16, 2020 12:52 pm
- Forum: General Science Questions
- Topic: midterm 2
- Replies: 4
- Views: 173
Re: midterm 2
In Lavelle's 17th lecture he said you will not need to calculate dipole moments. Just know that increase in bond length increases the dipole moments.
- Mon Nov 16, 2020 12:51 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Periodic Table Trends
- Replies: 4
- Views: 355
Re: Periodic Table Trends
The polarizing power increases from left to right across a period and decreases down columns of the periodic table.
Polarizability decreases from left to right and increases down columns of the periodic table.
Polarizability decreases from left to right and increases down columns of the periodic table.
- Thu Nov 12, 2020 9:52 pm
- Forum: Ionic & Covalent Bonds
- Topic: Sapling HW Question 13
- Replies: 3
- Views: 206
Re: Sapling HW Question 13
We know that a hydrogen bond forms when there is a hydrogen bonded to two very electronegative molecules. Both a nitrogen atom and oxygen atom, with an unshared pair of electrons, can form a hydrogen bond by bonding to a hydrogen (of a water molecule). Also, if a Hydrogen is already bonded to nitrog...
- Thu Nov 12, 2020 9:41 pm
- Forum: Lewis Structures
- Topic: Sapling #2-Formal Charge
- Replies: 3
- Views: 94
Re: Sapling #2-Formal Charge
You find formal charge using this formula: Formal Charge of Atom = Valence Electrons of Atom - # of Lone Electrons on Atom - # bonded electrons with Atom/2. - Valence Electrons of Atom - found using the periodic table of elements - # of Lone Electrons on Atom - these are the lone individual electron...
- Wed Nov 04, 2020 3:38 pm
- Forum: Student Social/Study Group
- Topic: Constants and Equations Page
- Replies: 8
- Views: 312
Re: Constants and Equations Page
Yep have to memorize but here is how I remember it:
Freddy Can't Vacant Nashville Before 2
FC = V - N - B/2
Not sure how helpful that is for you, but it sticks in my head.
Freddy Can't Vacant Nashville Before 2
FC = V - N - B/2
Not sure how helpful that is for you, but it sticks in my head.
- Wed Nov 04, 2020 3:33 pm
- Forum: Student Social/Study Group
- Topic: Favorite TV shows
- Replies: 277
- Views: 34266
Re: Favorite TV shows
I recently binged Grand Army and The Queen's Gambit on Netflix. would recommend both!
- Thu Oct 29, 2020 7:17 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: h vs. ħ?
- Replies: 11
- Views: 5374
h vs. ħ?
Can you explain the difference between h (6.62607015×10−34) and ħ (h-bar) (1.054571817×10−34) to me please?
And when do we use the 1) formula and the 2) formula?
1) ∆p ∆x ≥ h/4π
2) ∆p ∆x = (1/2) ħ
Thank youuuuu
And when do we use the 1) formula and the 2) formula?
1) ∆p ∆x ≥ h/4π
2) ∆p ∆x = (1/2) ħ
Thank youuuuu
- Thu Oct 29, 2020 7:33 am
- Forum: Student Social/Study Group
- Topic: Lavelle's Jokes
- Replies: 26
- Views: 2134
Re: Lavelle's Jokes
These 2 make me kinda sad :( But the drawings are cute.
- Mon Oct 26, 2020 3:17 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Constants, Equations, and Periodic Table
- Replies: 3
- Views: 260
Re: Constants, Equations, and Periodic Table
You should use the ones he emailed us.
Here are the links to them
Constants/Equations: https://lavelle.chem.ucla.edu/wp-conten ... ations.pdf
Periodic Table: https://lavelle.chem.ucla.edu/wp-conten ... _IUPAC.pdf
Here are the links to them
Constants/Equations: https://lavelle.chem.ucla.edu/wp-conten ... ations.pdf
Periodic Table: https://lavelle.chem.ucla.edu/wp-conten ... _IUPAC.pdf
- Mon Oct 26, 2020 3:14 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Calculator Tip
- Replies: 1
- Views: 231
Calculator Tip
Hey Guys I thought I would share this tip. I recommend storing constants in your calculator so you don't have to type them out all the time. This helps me be faster and not make silly mistakes (like incorrectly copying the constant value). How to do this is: 1) Enter the number in your calculator 2)...
- Mon Oct 26, 2020 2:59 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Sapling Homework Score
- Replies: 3
- Views: 157
Re: Sapling Homework Score
I think it is best to worry about that if it continues to happen after the due date since it will probably update everything once it is all due.
- Mon Oct 26, 2020 1:58 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm topics and information
- Replies: 8
- Views: 339
Re: Midterm topics and information
My guess is that you would be fine with just reading the textbook. From my understanding the textbook problems are the ones the exam is based on so making sure you understand that would be best. Also doing the audio visual practice problems.
- Mon Oct 26, 2020 1:52 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Sapling HW Q18
- Replies: 1
- Views: 93
Re: Sapling HW Q18
The atomic radius of atoms generally decreases from left to right across a period.And increase from top to bottom. Check out the image I attached. Also the gain of an electron adds more electrons to the outermost shell and the pull towards the nucleus so the pull becomes slightly weaker so it causes...
- Mon Oct 26, 2020 1:43 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Petition to Bring Music Back To Lectures [ENDORSED]
- Replies: 34
- Views: 1276
Re: Petition to Bring Music Back To Lectures [ENDORSED]
I love the music! It is so fun.