Search found 133 matches

by SophiaJenny3I
Sun Feb 21, 2021 10:21 pm
Forum: Student Social/Study Group
Topic: Chem 14B Posting on Chem Community
Replies: 11
Views: 47

Re: Chem 14B Posting on Chem Community

Hi! I think they count the number of posts based on your student ID number connected to your account. So I believe it shouldn't matter, but please correct me if I'm wrong.
by SophiaJenny3I
Sun Feb 21, 2021 10:21 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Liquids and Solids in Equilibrium Calculations
Replies: 6
Views: 15

Re: Liquids and Solids in Equilibrium Calculations

Yes! Solids and liquids are ignored when calculating the equilibrium constant. This is because their respective concentrations essentially stay constant throughout the reaction.
by SophiaJenny3I
Sun Feb 21, 2021 10:16 pm
Forum: Student Social/Study Group
Topic: Fave food
Replies: 99
Views: 205

Re: Fave food

I know this is such a typical answer, but my favorite food is pizza!!! Is anyone a fan of pineapple on pizza? I also love gnocchi, I've been making it in quarantine and it's a lot of fun!
by SophiaJenny3I
Sun Feb 21, 2021 10:14 pm
Forum: Administrative Questions and Class Announcements
Topic: Final
Replies: 32
Views: 86

Re: Final

Hi! I also didn't do as well as I wanted to on the final in 14A. I did all the textbook problems for the recent units, but I didn't re-visist the old textbook problems as much. That was definitely where I messed up. While I remembered the past problems to a certain extent, it wasn't as fresh in my m...
by SophiaJenny3I
Sun Feb 21, 2021 9:07 pm
Forum: Administrative Questions and Class Announcements
Topic: Chem 14 B Final
Replies: 27
Views: 125

Re: Chem 14 B Final

Yes the final is cumulative! One thing to note is to make sure you review past material as well (not just week 7-10). I made this mistake on the last final, and took way too much time on the actual exam trying to remember past concepts. While it's important to understand the current lessons, don't f...
by SophiaJenny3I
Fri Feb 19, 2021 9:14 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gas Constant R
Replies: 41
Views: 64

Re: Gas Constant R

Hi! Not necessarily. Always make sure you write out the units you have, and observe the unit you want and make sure everything else cancels out. This has helped me make sure I don't choose the wrong one! 8.314 is usually used when you want to end in J/kJ if you convert it.
by SophiaJenny3I
Fri Feb 19, 2021 9:11 pm
Forum: Student Social/Study Group
Topic: Post Midterm 2 De-stressing
Replies: 85
Views: 224

Re: Post Midterm 2 De-stressing

My family had a pizza night so that was a nice way to destress :). I have another midterm I'm taking tomorrow, but after that I will really be able to de-stress!!!
by SophiaJenny3I
Wed Feb 17, 2021 6:53 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 4D9 Explanation
Replies: 1
Views: 15

4D9 Explanation

Hi everyone! I was working through the textbook problems and got a bit tripped up on 4D9. I've attached a picture of the question below, does someone mind taking me through their logic? I understand you need to use enthalpies of formation, but I keep getting the wrong answer. Thank you!!! Screen Sho...
by SophiaJenny3I
Sun Feb 14, 2021 10:54 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Adiabatic System
Replies: 9
Views: 17

Re: Adiabatic System

Hi! An abdiabatic system means there is no heat flow (q = 0). Therefore, in the equation deltaU = q+w --> deltaU = w because q = 0. Hope this helps!
by SophiaJenny3I
Sun Feb 14, 2021 10:44 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Entropy
Replies: 9
Views: 23

Re: Entropy

Hi! I'm not sure if I remember that exactly. However, I think that statement means that the entropy of the universe is not going to favorably decrease. The universe favors disorder, not order (which would be caused by the decrease). Hopefully this is kind of close to what the statement means.
by SophiaJenny3I
Sun Feb 14, 2021 11:45 am
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Sapling #1wk5/6
Replies: 2
Views: 11

Re: Sapling #1wk5/6

Hi! Residual entropy is also known as positional entropy. This correlates to the number of possible positions/states in a system. However, if there is only 1 possible unique state, the residual entropy is 0. One thing that's important to note is switching the orientation of a symmetrical model will ...
by SophiaJenny3I
Sun Feb 14, 2021 11:37 am
Forum: Administrative Questions and Class Announcements
Topic: Lecture #16 Error
Replies: 6
Views: 34

Re: Lecture #16 Error

This has happened to me before! I just exit CCLE for a couple minutes or a half hour or so, then I come back and it normally works!
by SophiaJenny3I
Fri Feb 12, 2021 10:21 pm
Forum: Administrative Questions and Class Announcements
Topic: UA Sessions on Monday (Holiday)?
Replies: 3
Views: 49

UA Sessions on Monday (Holiday)?

Hi everyone! There's a chance I might've missed this in an announcement or something, but does anyone know if there'll be UA sessions on Monday (holiday)? No worries if not, I just wanted to plan ahead! Thanks :)
by SophiaJenny3I
Fri Feb 12, 2021 10:18 pm
Forum: Student Social/Study Group
Topic: Studying for Midterm 2
Replies: 45
Views: 182

Re: Studying for Midterm 2

A mistake that I've definitely made is focusing on the content that I'm pretty comfortable with. It's great you're being proactive!!! Just make sure you review the content you get wrong/are confused about sooner rather than later. While it's discouraging to review that content now, it'll help you la...
by SophiaJenny3I
Fri Feb 12, 2021 10:16 pm
Forum: General Science Questions
Topic: Study Tips for midterm
Replies: 24
Views: 64

Re: Study Tips for midterm

The UA sessions are SO helpful! I know Justin is doing a review on Thursday from 10AM-12PM (instead of the split up step up session and workshop). Highly recommend! I also like going through all the textbook problems on the outline. In reference to your other question, I think the module assessments...
by SophiaJenny3I
Fri Feb 12, 2021 10:12 pm
Forum: Administrative Questions and Class Announcements
Topic: 14C First or Second Pass
Replies: 10
Views: 71

Re: 14C First or Second Pass

I'll be using my first pass for Chem 14C! Personally, I want to do all I can to take these chem classes back to back!
by SophiaJenny3I
Thu Feb 11, 2021 2:18 pm
Forum: Student Social/Study Group
Topic: Classes for next quarter?
Replies: 127
Views: 412

Re: Classes for next quarter?

I'm planning on take Chem 14C, Chem 14BL, and continuing my biotech cluster!
by SophiaJenny3I
Sun Feb 07, 2021 11:55 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Units
Replies: 10
Views: 37

Re: Units

Hi! Definitely just focus on what is given in the problem. It can be either Kelvin or Celsius, but both temperature values have to both be in kelvin and celsius in order to make sure the change in temp is accurate. I always like to write everything out so I avoid any silly mistakes!
by SophiaJenny3I
Sun Feb 07, 2021 11:52 pm
Forum: Student Social/Study Group
Topic: Post Midterm 1...
Replies: 39
Views: 148

Re: Post Midterm 1...

The workshops are SUCH a great resource. The UAs are all super helpful and have so many problems to go through. What's great about them is, not only do you set aside time to work on chemistry outside of lecture/textbook problems, but you can use these problems to review later! Before an exam, I go t...
by SophiaJenny3I
Sun Feb 07, 2021 11:48 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: How can we change the energy in an isolated system?
Replies: 4
Views: 11

Re: How can we change the energy in an isolated system?

In an isolated system, nothing exchanges with the surroundings. So, you can't change the energy as you can't add/remove a certain amount of substance, heat/cool the system, do work on it, etc. Hope this helps!
by SophiaJenny3I
Fri Feb 05, 2021 10:14 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Closed Systems
Replies: 14
Views: 68

Re: Closed Systems

Hello! I think all you need to focus on with closed systems is "stuff" can't go in and out. Only energy can exchange with the surroundings, and it can also be heated. However, I remember in lecture that one of the ways we can change the energy of a closed system is to do work (such as comp...
by SophiaJenny3I
Fri Feb 05, 2021 10:09 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Thermochemistry Equations?
Replies: 7
Views: 32

Re: Thermochemistry Equations?

Ryan Laureano 3I wrote:I actually remembered a quick trick for gibbs free energy. delta g = -RTlnK or ratlink
This may or may not help but its good to know.

I use this one too!!! It's always helped me remember it, even as silly as it may sound!
by SophiaJenny3I
Fri Feb 05, 2021 10:07 pm
Forum: General Science Questions
Topic: Careless Mistakes
Replies: 54
Views: 233

Re: Careless Mistakes

I can definitely relate to this! Just focus on taking your time, especially on an exam. If you don't know a problem, skip it so you don't rush through the ones you know. I normally try to leave time to go back and quickly redo the problems to a certain extent, or at least go back through my work aga...
by SophiaJenny3I
Fri Feb 05, 2021 10:05 pm
Forum: Student Social/Study Group
Topic: Study routine.
Replies: 51
Views: 99

Re: Study routine.

Hi! I love doing as many practice problems as I can. I aim to go through all the textbook problems before the exam, because they're such a good barometer for what we need to know. Also, go to workshops each week! It's a good way to stay on top of the material and challenge yourself! Also, they make ...
by SophiaJenny3I
Thu Feb 04, 2021 5:55 pm
Forum: Student Social/Study Group
Topic: Studying When You Don't Want to
Replies: 48
Views: 136

Re: Studying When You Don't Want to

Hi! When I have a lot of tasks to accomplish/complete, I love to make a list! While a list seems daunting, they are smaller, tangible ways for you to feel accomplished. I use Notes on my computer to make a checklist, and when I complete a task, I click on the bubble and it puts a little checkmark by...
by SophiaJenny3I
Sun Jan 31, 2021 11:03 pm
Forum: Ideal Gases
Topic: Exo vs Endothermic
Replies: 29
Views: 105

Re: Exo vs Endothermic

Hi! Just remember that forming bonds is exothermic (the release of energy), while breaking bonds is endothermic (takes up/requires energy)! When thinking about the effect of a temperature change, I like to think about it like this: for exothermic reactions, the deltaH is negative. If the temperature...
by SophiaJenny3I
Sun Jan 31, 2021 8:10 pm
Forum: Administrative Questions and Class Announcements
Topic: 14C?
Replies: 23
Views: 122

Re: 14C?

Hi! Next quarter I plan on taking 14C and 14BL! I definitely want to keep all the chem classes together so the concepts stay fresh in my mind and it's a nice progression through the material.
by SophiaJenny3I
Sun Jan 31, 2021 8:08 pm
Forum: Student Social/Study Group
Topic: How to relax
Replies: 126
Views: 717

Re: How to relax

I love to go on walks once a day to relax! It definitely helps clear my mind and allows me to be slightly active! I also love to read a good book or just watch some Netflix :)
by SophiaJenny3I
Sun Jan 31, 2021 7:48 pm
Forum: Administrative Questions and Class Announcements
Topic: Grading for Chemistry Community Posts
Replies: 12
Views: 60

Re: Grading for Chemistry Community Posts

Hi! It's the amount of posts. Also, asking questions count towards the number of posts/week! Definitely focus on doing the 5 posts/week.
by SophiaJenny3I
Sat Jan 30, 2021 2:48 pm
Forum: Student Social/Study Group
Topic: Favorite TV shows
Replies: 189
Views: 1206

Re: Favorite TV shows

Oh my goodness! ^I absolutely LOVE Psych! I can't believe Taylor K said that, I've met very few people who know about Psych. I cannot recommend it enough!!! My other favorites are Schitt's Creek, Young and Hungry, The Office, How I Met Your Mother, and The Crown. I LOVE PSYCH!!! I feel like no one'...
by SophiaJenny3I
Fri Jan 29, 2021 9:21 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: R Constant
Replies: 89
Views: 243

Re: R Constant

Hi! You just have to look at the units the problem gives you. Normally, it's deciding between the one with bar and atm, and the problem will tell you which to use! If you're ever uncertain, write out all the units when you're calculating a value using R and double check that the units cancel and you...
by SophiaJenny3I
Fri Jan 29, 2021 9:20 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Inert gas
Replies: 24
Views: 95

Re: Inert gas

Hi! When you're thinking about the effect of pressure on a system, you need to focus on the volume. When an inert gas is added, it doesn't change the volume. It's non-reactive and doesn't affect the concentrations of the molecules in the system.
by SophiaJenny3I
Fri Jan 29, 2021 7:20 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Taking the Anti-Log
Replies: 36
Views: 111

Re: Taking the Anti-Log

Hi! To take the antilog of something (whether it be to go from pH ==> [H30+], pOH ==> [OH-], pKa ==> Ka, etc.) you just take that number and make it the negative power of 10.
For example: pH = 6 --> 10^-6 --> 1 x 10^-6. Hope this helps!
by SophiaJenny3I
Thu Jan 28, 2021 1:31 pm
Forum: Student Social/Study Group
Topic: Midterm 1
Replies: 3
Views: 34

Re: Midterm 1

Here's the link: https://lavelle.chem.ucla.edu/wp-conten ... dterm1.pdf
It explains everything and is super helpful :)
by SophiaJenny3I
Wed Jan 27, 2021 11:10 am
Forum: Bronsted Acids & Bases
Topic: Amphiprotic vs Amphoteric
Replies: 1
Views: 20

Amphiprotic vs Amphoteric

Hi everyone! Just wanted to confirm the difference between amphoteric and amphiprotic. Amphiprotic means a molecule can ACT as both a proton donor and proton acceptor (using the Bronsted definition of acids and bases), while amphoteric means a molecule can REACT with both acids and bases. Is this co...
by SophiaJenny3I
Sun Jan 24, 2021 10:59 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Clarification for Sampling #7
Replies: 10
Views: 47

Re: Clarification for Sampling #7

Hi! You're correct you do have to find the kB value first. This is because you're specifically looking for the pH of the salt NaClO, which is identified in the problem as a weak base. So yes, you have to convert to Kb from Ka!
by SophiaJenny3I
Sun Jan 24, 2021 10:57 pm
Forum: Student Social/Study Group
Topic: Exam Duration
Replies: 7
Views: 40

Re: Exam Duration

I'm pretty sure last time there was an extra five minutes or so just in case. However, don't be concerned. When I took the first midterm in 14A, my Respondus lockdown browser glitched and crashed my computer so I had to borrow my mom's and download it. That took a solid five minutes but once I click...
by SophiaJenny3I
Fri Jan 22, 2021 10:45 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Concentration X
Replies: 4
Views: 19

Re: Concentration X

Hi! If the K value is < 10^-4 we can use the approximation that the amount of x is very small relative to the initial concentration. Therefore, the difference between the initial and the change is just the initial. It's important to understand that x is NOT zero, but insignificant to the change in i...
by SophiaJenny3I
Fri Jan 22, 2021 9:50 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: H2O and K
Replies: 11
Views: 33

Re: H2O and K

Hi! Yes, since H20 is in its gas form, we include it in the equilibrium constant. For equilibrium constants, we use concentrations of aqueous solutions and gases. We exclude solids and liquids (that are often solvents, in the case of water). H20 in its liquid form is omitted because the change in so...
by SophiaJenny3I
Fri Jan 22, 2021 7:59 pm
Forum: Student Social/Study Group
Topic: Midterm Study Tips
Replies: 41
Views: 150

Re: Midterm Study Tips

Hi! The UA sessions are SUPER helpful. Definitely recommend those. Also, going through all the textbook problems in the outlines! They're great practice. I like to read the textbook sessions as well and take down some main notes, just so I know I have the concepts down! If I have time, I also like t...
by SophiaJenny3I
Fri Jan 22, 2021 2:19 pm
Forum: General Science Questions
Topic: Gases and Reactions
Replies: 4
Views: 30

Re: Gases and Reactions

Yes I agree. I would assume it's safe to say that if the word problem says it is oxygen gas, that it's diatomic as that's it's structure. Same with the other diatomic gases: nitrogen, fluorine, hydrogen, and chlorine.
by SophiaJenny3I
Fri Jan 22, 2021 2:14 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Increasing pressure
Replies: 23
Views: 107

Re: Increasing pressure

Hi! An inert gas is basically a gas that won't react with anything in the reaction. The system does not respond to the inert gas because while the pressure goes up, the volume is NOT changing. And that's the key element. The reaction staying in equilibrium is dependent on the concentrations. The con...
by SophiaJenny3I
Fri Jan 22, 2021 10:06 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Studying for Midterm #1
Replies: 63
Views: 181

Re: Studying for Midterm #1

Hi! I typically read the textbook go through all the extra problems from the outlines. They are super helpful and are great at pointing out concepts that I'm shaky on. The workshop sessions held by the UAs are super helpful as well! I like to go over those problems and redo them before the midterm. ...
by SophiaJenny3I
Sun Jan 17, 2021 11:16 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Initial Concentrations
Replies: 7
Views: 46

Re: Initial Concentrations

Hi! You just have to look at what's given to you. Since in #10 you are given both initial concentration, plug those into the ICE table and work from there. I've found that these problems make a lot more sense when you write out everything you know, and then begin to fill in the blanks to figure out ...
by SophiaJenny3I
Sun Jan 17, 2021 8:34 pm
Forum: Student Social/Study Group
Topic: Sapling Homework
Replies: 6
Views: 35

Re: Sapling Homework

Often when you get the question wrong, a feedback note pops up! These can be super helpful and really can walk you through the problem. Definitely don't click "I give up" as I'm pretty sure you won't get credit, and it's definitely not worth it! Try the feedback from the different answers ...
by SophiaJenny3I
Sun Jan 17, 2021 6:12 pm
Forum: Student Social/Study Group
Topic: Comfort Movies
Replies: 128
Views: 343

Re: Comfort Movies

I love watching any Star Wars movie. For a fun silly one, I love Despicable Me!
by SophiaJenny3I
Fri Jan 15, 2021 8:05 pm
Forum: Student Social/Study Group
Topic: Approaching Outlines
Replies: 14
Views: 69

Re: Approaching Outlines

Hi! During 14A I would typically read the textbook section and immediately do the problems following it to help keep me on track. I typically did the textbook problems a couple days after it was taught in lecture, and gradually caught up as I approached the midterm. My goal was to finish the majorit...
by SophiaJenny3I
Fri Jan 15, 2021 8:02 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Molecular phases
Replies: 6
Views: 20

Re: Molecular phases

Hi! So basically (aq) stands for aqueous which basically means the substance is dissolved in water. (l) stands for liquid and that means the substance is in it's pure liquid state. We don't include H20 when calculating the equilibrium constant because it's a pure substance. The molar concentration o...
by SophiaJenny3I
Fri Jan 15, 2021 7:55 pm
Forum: Ideal Gases
Topic: Thermodynamics in Equilibirum
Replies: 6
Views: 51

Re: Thermodynamics in Equilibirum

Hi! Thermodynamics hasn't been covered in-depth yet so I wouldn't worry too much about it. Probably understanding endothermic/exothermic reactions for now is perfect. If you look ahead to the outlines, we will be covering it in Outline 4! Hope this helps!
by SophiaJenny3I
Fri Jan 15, 2021 7:38 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Week 2 HW
Replies: 8
Views: 53

Re: Week 2 HW

Just remember that hydronium concentration [H30+] is related to pH and hydroxide concentration [OH-] is related to pOH. So, since you're given the pH, you need to convert to pOH. You do this by using the equation 14 = pH + pOH. Rearrange the equation to solve for pOH: pOH = 14-pH. Then, once you hav...
by SophiaJenny3I
Fri Jan 15, 2021 7:25 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 6D1 - tables?
Replies: 2
Views: 19

Re: 6D1 - tables?

Yes! It tells you to refer to them, as you need the Ka values to solve this problem!
by SophiaJenny3I
Fri Jan 08, 2021 6:23 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Confusion with terms
Replies: 9
Views: 93

Re: Confusion with terms

Yes! It all means the same thing. Dr. Lavelle has mentioned he doesn't prefer the "shifting" term just because it's misleading, since equilibrium doesn't shift. However, they're all right and the same thing! And yes, when the forward is favored, the reaction favors the products because the...
by SophiaJenny3I
Fri Jan 08, 2021 6:19 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Clarification of terminology
Replies: 15
Views: 126

Re: Clarification of terminology

Yes! It all means the same thing. Dr. Lavelle has emphasized however that the equilibrium "shifting" is a misleading description since the equilibrium doesn't shift, it just favors the reactants. But, they're all correct!
by SophiaJenny3I
Fri Jan 08, 2021 6:16 pm
Forum: Administrative Questions and Class Announcements
Topic: Audio-Visual Topics
Replies: 13
Views: 80

Re: Audio-Visual Topics

I'm pretty sure it's just for equilibrium, since last quarter we only had them for the beginning to make sure we all were on the same page at the start of the course.
by SophiaJenny3I
Fri Jan 08, 2021 5:34 pm
Forum: Ideal Gases
Topic: PV=nRT and concentration
Replies: 27
Views: 131

Re: PV=nRT and concentration

Hi! So, in the PV = nRT equation, here are what all the variables represent which will help. P = pressure in atm, V = volume in L, n = moles, R = gas constant ( 8.206 x 10-2 L·atm·K-1·mol-1, for example), and T = temperature in K. Most important thing about figuring this out, is understanding Molari...
by SophiaJenny3I
Thu Jan 07, 2021 10:55 pm
Forum: Student Social/Study Group
Topic: Study Habits
Replies: 96
Views: 321

Re: Study Habits

Hi! I've found that my biggest problem with studying is I never spend enough time on the stuff I'm shaky on. I like going through concepts I know how to do, just to confirm I do, but it ends up taking way too much time. While it can be daunting to do practice problems on concepts you don't like/find...
by SophiaJenny3I
Tue Jan 05, 2021 7:59 am
Forum: Student Social/Study Group
Topic: Advice for someone who didn't take 14A with professor Lavelle
Replies: 61
Views: 328

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

Hi! The UA sessions are super helpful! We always go over some practice problems, so they're awesome when you're reviewing later on for the midterms. Also, it's a good chance to check what you know and see what you're a bit shaky on. The textbook problems in the unit outlines are a lifesaver, and rea...
by SophiaJenny3I
Wed Dec 16, 2020 8:10 pm
Forum: General Science Questions
Topic: final timing
Replies: 25
Views: 122

Re: final timing

Yes I definitely ran out of time too. I caught myself obsessing over problems that I wasn't sure about, so I was rushing at the end. I've definitely learned my lesson from that and hopefully can take that lesson into 14B! We got this guys! :)
by SophiaJenny3I
Sat Dec 12, 2020 10:24 am
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Hard/Soft Water
Replies: 5
Views: 43

Hard/Soft Water

Hi guys! Could someone please clarify the differences between hard and soft water? Thank you!
by SophiaJenny3I
Fri Dec 11, 2020 8:31 pm
Forum: Student Social/Study Group
Topic: Struggling on topics
Replies: 6
Views: 49

Re: Struggling on topics

Whenever I'm struggling with a topic, I like to reword the conceptual ideas and write them down in my own words. This forces me to identify what I'm confused about. Also, I like doing a lot of practice problems, especially from this textbook. If you are having trouble, it's ok to look at the key and...
by SophiaJenny3I
Fri Dec 11, 2020 8:29 pm
Forum: Hybridization
Topic: Focus 2: 2.45 Problem
Replies: 3
Views: 36

Re: Focus 2: 2.45 Problem

Please post the entire question for other people to reference. But for the logic of this problem, the most significant Lewis structure of a molecule is the one with the smallest net formal charges, in other words, the lewis structure where the formal charges are closest to 0. Thank you so much! Thi...
by SophiaJenny3I
Fri Dec 11, 2020 8:26 pm
Forum: Student Social/Study Group
Topic: Thoughts on Switching Majors?
Replies: 31
Views: 288

Re: Thoughts on Switching Majors?

Hi! Definitely choose something you're passionate about. This will help motivate you in the future and make you love what you do! Think about what makes you happy. Do you love to write? Ask inquisitive questions and interview people? Analyze movies and TV shows? Play an instrument? Is there a partic...
by SophiaJenny3I
Fri Dec 11, 2020 4:46 pm
Forum: Student Social/Study Group
Topic: Final
Replies: 18
Views: 125

Re: Final

There will definitely be some from the textbook. Make sure to review quantum specifically since that was the most time we spent on a section!
by SophiaJenny3I
Fri Dec 11, 2020 4:42 pm
Forum: Industrial Examples
Topic: Chemotherapy
Replies: 18
Views: 399

Re: Chemotherapy

Jade_Tai_2L wrote:I only remember Dr. Lavelle going over Cisplatin-- do we have to know others?


I'm pretty sure the only one we'd have to know is cisplatin, and possibly why transplatin is its ineffective counterpart.
by SophiaJenny3I
Thu Dec 10, 2020 10:06 pm
Forum: Hybridization
Topic: Focus 2: 2.45 Problem
Replies: 3
Views: 36

Focus 2: 2.45 Problem

Hey guys! Could someone please explain their logic to determining the most "important" Lewis structure in this problem? I circled this one and came back to it but I'm still a bit confused. Thanks in advance!
by SophiaJenny3I
Sun Dec 06, 2020 8:40 pm
Forum: Sigma & Pi Bonds
Topic: Pi bonds
Replies: 7
Views: 53

Re: Pi bonds

I am almost certain that Dr. Lavelle said in lecture we don't need to know which is which, it's just a matter of knowing the different properties and how/when pi bonds exist!
by SophiaJenny3I
Sun Dec 06, 2020 8:39 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8753
Views: 1489815

Re: Post All Chemistry Jokes Here

What's a chemist's favorite dog?
A Laboratory retriever! :)
by SophiaJenny3I
Sun Dec 06, 2020 8:36 pm
Forum: Naming
Topic: "(en)" Sapling
Replies: 19
Views: 136

Re: "(en)" Sapling

Hi! en is shorthand for ethylenediamine (H2NCH2CH2NH2). It's a bidentate ligand, so when it's in a complex it contributes two to the coordination number. Hope this helps!
by SophiaJenny3I
Sun Dec 06, 2020 8:29 pm
Forum: Naming
Topic: Order of Ligands/naming
Replies: 28
Views: 146

Re: Order of Ligands/naming

Hi! This is more in general for coordination compounds, but here's a resource that has been super helpful that is on Dr. Lavelle's website: https://lavelle.chem.ucla.edu/wp-conten ... pounds.pdf
Hope this helps!
by SophiaJenny3I
Fri Dec 04, 2020 11:10 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Stability based on Resonance
Replies: 4
Views: 49

Re: Stability based on Resonance

Hi! So here's some of the main points I've gathered about resonance. One thing that's important to remember is that a molecule with resonance doesn't change between these different structures. A resonance hybrid is a merging of structures. In addition, the electrons in the different positions are de...
by SophiaJenny3I
Fri Dec 04, 2020 10:45 pm
Forum: General Science Questions
Topic: study methods/recs
Replies: 37
Views: 333

Re: study methods/recs

Definitely go to all the review sessions you can that Dr. Lavelle has set up. The UA workshops have been such a great resource for me, and provide even more practice problems for the future. Also, I catch myself doing this a lot so don't just practice the stuff you know. It's super easy and comforta...
by SophiaJenny3I
Fri Dec 04, 2020 10:39 pm
Forum: Student Social/Study Group
Topic: How are you?
Replies: 117
Views: 873

Re: How are you?

I'm good! Getting so excited for Christmas and break! Definitely a bit nervous for all the finals though.
by SophiaJenny3I
Fri Dec 04, 2020 9:22 pm
Forum: Student Social/Study Group
Topic: Practice Exam for Final
Replies: 23
Views: 281

Re: Practice Exam for Final

Darren1e wrote:By studying homework problems, are you referencing sapling or the textbook?

I think mainly focus on the textbook problems, but it wouldn't hurt to give the Sapling ones a glance!
by SophiaJenny3I
Tue Dec 01, 2020 7:50 pm
Forum: Administrative Questions and Class Announcements
Topic: Final exam (fall 2020 quarter)
Replies: 20
Views: 237

Re: Final exam (fall 2020 quarter)

Hi! In the Week 10: Final Review Sessions document it describes how the material will be weighted. "Final covers all material (approximately weighted to the amount of time covered in the syllabus). Quantum was the biggest section." Hope this helps clarify!
by SophiaJenny3I
Sun Nov 29, 2020 10:27 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Sapling #15
Replies: 4
Views: 53

Re: Sapling #15

Hi! So a pi bond only happens in double and triple bonds. If there is a double bond, it is one sigma bond and one pi bond. If there is a triple bond, it is one sigma bond and TWO pi bonds. You can't rotate pi bonds because they are parallel side by side and that would break the bond. The sigma bond ...
by SophiaJenny3I
Sun Nov 29, 2020 10:16 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Sapling 17
Replies: 3
Views: 45

Re: Sapling 17

Hi! This question confused me a bit as well, but once I figured it out I clicked on the "solution" button on the homework for that question and the explanation was great! Here it is: "Resonance structures are multiple Lewis structures that collectively represent a molecule. Resonance ...
by SophiaJenny3I
Sun Nov 29, 2020 10:10 pm
Forum: Student Social/Study Group
Topic: Studying for Final Exam
Replies: 57
Views: 392

Re: Studying for Final Exam

I'll make sure I get through all the textbook problems for this unit, and then go back and review all the Sapling homework for a good outline of problems. I'll also go back and do most of the textbook problems from previous units if I can, and go through workshop problems.
by SophiaJenny3I
Fri Nov 27, 2020 6:11 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone Pair VSEPR
Replies: 5
Views: 57

Re: Lone Pair VSEPR

Hi! So the lone pairs actually repel the bonding regions. There is more repulsion between a lone pair and a bonding region, rather than a bonding region with a bonding region. Therefore, the lone pair repels the bonding region, and it goes closer to the other bonding region. This is what makes the a...
by SophiaJenny3I
Fri Nov 27, 2020 6:05 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: d orbitals
Replies: 7
Views: 80

Re: d orbitals

Hi! So any orbital, as well as a d orbital, can only hold a max of 2 electrons and these electrons must have opposite spins. If you're a visual person, it helps to look at the periodic table. The d subshells are basically represented by the transition metals. Each row of transition metals has 10 ele...
by SophiaJenny3I
Fri Nov 27, 2020 5:51 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Sapling Weeks 7-8 #16
Replies: 6
Views: 72

Re: Sapling Weeks 7-8 #16

Hi! A molecule has delocalized pi bonds when it has resonance with double or triple bonds. So, think about what has the capacity to double bond or triple bond in the first place, and if these double or triple bonds can be "moved" around.
by SophiaJenny3I
Fri Nov 27, 2020 5:48 pm
Forum: Properties of Electrons
Topic: degenerate orbital
Replies: 6
Views: 90

Re: degenerate orbital

Hi! So degenerate orbitals are orbitals with the same energy. When the the value of n and l is the same, they are degenerate orbitals. For example, in the 2p subshell, there are 3 degenerate orbitals. The only exception to degenerate orbitals is when the same value of n has DIFFERENT values of l in ...
by SophiaJenny3I
Fri Nov 27, 2020 3:02 pm
Forum: Significant Figures
Topic: 40. versus 40
Replies: 23
Views: 189

Re: 40. versus 40

Hi! Here's the link to Dr. Lavelle's sig fig cheat sheet you can find on his website.
https://lavelle.chem.ucla.edu/wp-conten ... OUT_SF.pdf
by SophiaJenny3I
Tue Nov 24, 2020 5:35 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm 2 Results
Replies: 10
Views: 132

Re: Midterm 2 Results

Hannah Chang 3E wrote:Is there a way to view the distribution and average score of the class?

Hi Hannah! Dr. Lavelle said the class average was an 82% in his email.
by SophiaJenny3I
Fri Nov 20, 2020 10:33 pm
Forum: General Science Questions
Topic: # of chem posts
Replies: 27
Views: 334

Re: # of chem posts

Also, make sure you have 5 posts/week. The chem posts don't carry over week by week if you have more than 5. You can check the specifics by clicking the 3 bars next to quick links and clicking "Your posts." There, you can check when you posted by clicking on the particular topic and search...
by SophiaJenny3I
Fri Nov 20, 2020 6:21 pm
Forum: Student Social/Study Group
Topic: Study Tips for Final Exam
Replies: 57
Views: 444

Re: Study Tips for Final Exam

Hi! I'll definitely continue attending workshops, those are super helpful. Also, the workshops give you even more problems to practice later. I'll probably go through my notes and rewrite them in my own words as well, just to make sure I have a grasp on the conceptual facts/ideas. I'll make sure to ...
by SophiaJenny3I
Fri Nov 20, 2020 6:00 pm
Forum: Lewis Structures
Topic: Midterm Q
Replies: 2
Views: 49

Re: Midterm Q

We're good for now! Once we officially learn nomenclature that's when we'll have to know the formulas associated with those names. Dr. Lavelle will let us know when that happens.
by SophiaJenny3I
Fri Nov 20, 2020 5:59 pm
Forum: Octet Exceptions
Topic: textbook 2C.3 d)
Replies: 4
Views: 49

Re: textbook 2C.3 d)

I agree with the comments above! It's very unstable to have a charge on the central atom. Since oxygen is very electronegative, it wants the extra electron and can thus hold the negative charge. So, the one double bond is the best option.
by SophiaJenny3I
Fri Nov 20, 2020 5:47 pm
Forum: Administrative Questions and Class Announcements
Topic: Question about Chem Community Posts
Replies: 5
Views: 66

Re: Question about Chem Community Posts

Also! Make sure that your comments have the proper amount for each week. You can get a max of 5 points for 5 posts each week, but they don't carry over. You can check this by looking at your posts by clicking on the 3 bars in the top left. Then, you can scroll through and find your comment and see w...
by SophiaJenny3I
Tue Nov 17, 2020 12:19 pm
Forum: Administrative Questions and Class Announcements
Topic: Enrollment into Chemistry 14B
Replies: 4
Views: 51

Re: Enrollment into Chemistry 14B

I'm sorry I'm honestly not sure. I know I had to enroll in math first last quarter since it was a required coreq so I'm not sure what the case there would be. Are you still in contact with your NSA? Maybe you can ask them? If not, I still have my NSA's contact info so maybe message me your email and...
by SophiaJenny3I
Tue Nov 17, 2020 11:59 am
Forum: Administrative Questions and Class Announcements
Topic: Enrollment into Chemistry 14B
Replies: 4
Views: 51

Re: Enrollment into Chemistry 14B

Yes! So the possible co-reqs for Chem14B are Life Science 30B, Mathematics 31B or Mathematics 3B! So either of those three are fine to take either before/while you're taking 14B! If you ever need to figure out what the co-reqs or pre-recs are, click the yellow exclamation point triangle next to the ...
by SophiaJenny3I
Sun Nov 15, 2020 11:05 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: Sapling #20
Replies: 2
Views: 10

Re: Sapling #20

Hi! So when you draw out the CH3CHO molecule you see that the hydrogen doesn't actually bond to the oxygen, only carbon. The oxygen bonds to a carbon. Therefore, there isn't a O-H bond present, so hydrogen bonding is not a factor.
by SophiaJenny3I
Fri Nov 13, 2020 9:07 pm
Forum: Ionic & Covalent Bonds
Topic: Textbook problem 2D. 5
Replies: 2
Views: 25

Re: Textbook problem 2D. 5

The C - F bond actually has a large difference in electronegativity compared to the C - H bond, so CF4 is actually more ionic. In simpler terms, F really wants another electron cause it only needs 1 more to make a complete octet. Also, this is in the 2p shell, so the electrons are really held tightl...
by SophiaJenny3I
Fri Nov 13, 2020 8:37 pm
Forum: Resonance Structures
Topic: Oxidation numbers
Replies: 5
Views: 32

Re: Oxidation numbers

Hi! Oxidation numbers are SUPER important, as they contribute to the total number of valence electrons in an atom or molecule! Normally, an oxidation number should be given if the structure is drawn out. The drawn out molecule will be surrounded by brackets and the oxidation number will be at the to...
by SophiaJenny3I
Fri Nov 13, 2020 8:22 pm
Forum: Resonance Structures
Topic: Counting resonance structures
Replies: 1
Views: 41

Re: Counting resonance structures

Hi! I think a main thing to focus on with resonance structures are how many times the bonds can be changed position-wise based on what's available. Remember that all resonance structures of a certain molecule are equal in energy, so there aren't infinite possible ways to change it. I'm pretty sure i...
by SophiaJenny3I
Fri Nov 13, 2020 8:04 pm
Forum: Administrative Questions and Class Announcements
Topic: Midtern #2
Replies: 6
Views: 39

Re: Midtern #2

We can use the same sheets as the first midterm! Definitely print it all out just in case. The periodic table is a must-have, and the equation sheet will just be good to have just in case. Scratch paper too!
by SophiaJenny3I
Fri Nov 13, 2020 8:04 pm
Forum: Ionic & Covalent Bonds
Topic: Orbitals
Replies: 3
Views: 30

Re: Orbitals

Basically, it's how scientists figured out the characteristics of orbitals in the first place and proved them. Schrodinger's equation show's us the wave function of an electron. Also, from the wave function squared, we see a probability plot which represents how electrons are present in the orbitals...
by SophiaJenny3I
Sun Nov 08, 2020 10:59 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: E-Configuration
Replies: 3
Views: 18

Re: E-Configuration

Hi! So the reason why there's a difference between those two elements is Ca doesn't actually have electrons in 3d, while Sc does. You didn't write it wrong! The easiest way for me to see this is to follow along on the periodic table. When you follow along, you see that 4s is actually before the 3d. ...
by SophiaJenny3I
Sun Nov 08, 2020 10:50 pm
Forum: Lewis Structures
Topic: expanded/smaller octets
Replies: 6
Views: 25

Re: expanded/smaller octets

Hi! So there are three elements that we should know that can have an expanded octet, meaning they don't have to follow the octet rule (aka they can have more than 8 valence electrons). Those are P, S, and Cl. When I went to a workshop, the UA called it the "pascal" group and that helps me ...
by SophiaJenny3I
Sun Nov 08, 2020 10:36 pm
Forum: Student Social/Study Group
Topic: Midterm 2
Replies: 28
Views: 195

Re: Midterm 2

Hi! For me, the workshops were the most helpful. It's a great way to test your knowledge when you go, and also have some problems to practice before the midterm! It's a win-win! Also, I did all the textbook problems and that really helps as well. In my opinion, practice is the best way to study for ...
by SophiaJenny3I
Sun Nov 08, 2020 10:33 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm 1 answer key
Replies: 13
Views: 108

Re: Midterm 1 answer key

I don't think we'll be able to directly see a Midterm 1 key, but Dr. Lavelle said he will go over commonly missed problems on Midterm 1 before the final. So you'll probably be able to figure out what you missed then!

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