CHEMISTRY COMMUNITY

Nadya Higgins 3F

I was writing notes on a tablet in the beginning of the quarter. I took a picture of the slides and annotated them with the things he said. This saved me time but I still felt like I wasn't learning. I switched over to hand-writing them with pen and paper and started to take the time to pause the le...

Nadya Higgins 3F

Probably wednesday and reviewing is important!

Nadya Higgins 3F

Lavelle's example of the multi-laned highway and exit was pretty helpful. It doesn't matter how many lanes and how fast the cars are going on the highway; the rate of cars leaving the highway in the end will be based on the the single-laned exit. The cars can only leave as fast as the single-lane al...

Nadya Higgins 3F

I've been really burned out too (mostly b/c everything's online), but I usually try to give myself small rewards for doing stuff or just tell myself that I need to at least get a certain amount of stuff done by the end of the day. Checklists have been helpful for me too.

Nadya Higgins 3F

textbook problems are always helpful for the final!

Nadya Higgins 3F

Definitely do the textbook problems and make sure you understand things conceptually

Nadya Higgins 3F

I believe if a positive E naught value means it is spontaneous

Nadya Higgins 3F

I'll try to separate my work and my relaxing place; so if I ever go on a break, I make sure to leave my desk and go to my bed or the couch or something. This helps me to subconsciously separate the place I should be concentrated and the places I can relax. This can help when I take tests because I'v...

Nadya Higgins 3F

when a system does work, it is negative; but when surroundings do work on a system, it's positive

Nadya Higgins 3F

it wouldn't be a state function because you can't rely on just a final and initial value

Nadya Higgins 3F

after MT2 I had my LS30B midterm and also had classes and a group project to do; I also had to go to my part-time yesterday and will have to today after catching up on last week's lectures; so I haven't had much time to relax! However, I did make some time after work last night to watch The Queen's ...

Nadya Higgins 3F

B has larger molecules (which means less moving components overall in the container) and they are not vibrationally active. Generally when I hear not active, I immediately think less entropy, because entropy is a like a measure of chaos. C also has larger molecules, but in this case they are active,...

Nadya Higgins 3F

I was a bit confused as well. From my understanding though, I think ∆G° represents the standard free energy change. So maybe just ∆G represents free energy change when the system is not at equilibrium?

Nadya Higgins 3F

sometimes I find it helpful to write out everything I know and teach the material to myself by saying things out loud. Watching videos on explanations help too. I've also been feeling very uncertain about this midterm...especially with how my last one went haha. But it's important to just take thing...

Nadya Higgins 3F

I would agree with others that using your first pass may be better!

Nadya Higgins 3F

yup as the person above said, all you have to do once you've found the moles is to plug in all of your known values into the nCvlnT2/T1 equation. Make sure your temperature values are converted to Kelvins

Nadya Higgins 3F

I think it depends on the UA but I've been to some sessions that reviewed midterm topics beforehand.

Nadya Higgins 3F

Hey there! I also work a part-time job and at the moment I'm generally working around 15 hours plus a week. It's been a bit of a struggle balancing that with classes, especially since even if I have some time to do school work after a shift, I'm often too tired to concentrate. It's been really diffi...

Nadya Higgins 3F

N is the number of particles. degeneracy is found by raising the number of possible arrangements by the number of particles. So because there were 4 CO molecules, and 2 possible arrangements for each, W=2^4=16.

Nadya Higgins 3F

heat lost by a system is taken up by its surroundings, and vice versa

Nadya Higgins 3F

They're being posted today..! Pretty nervous..

Nadya Higgins 3F

No curve most likely; but Lavelle's form of a curve was the bonus question and also the fact that having a 50% in the class still means you pass with a C- I believe

Nadya Higgins 3F

week 3/4 homework is due week 5 sunday night; week 5/6 homework is due week 6 sunday night

Nadya Higgins 3F

It may update after you post more; if not, rest assured that it will all be updated next time grades are put in!

Nadya Higgins 3F

I don't know about you guys but this post midterm depression is hitting like a truck. I did eat like 10 of those Toll House cookies to numb the pain. We can only look up from here and learn from our mistakes though. Congrats everyone! Oh man, I totally get that. I felt pretty down after the midterm...

Nadya Higgins 3F

I took a 3 hour nap after!! Self care <3 I hope you and anyone reading this enjoyed the rest of friday after the exam! <3 keep trying u can do! Yes thank you! I watched some shows, tried to be social and talk with friends, and also played some games with my brother, so in the end I would say it was...

Nadya Higgins 3F

I would treat myself but I still have so much homework so I want to finish that so I have Sunday to chill :) Ah I totally get that! Hopefully it all went smoothly and you got what you needed to done! Also, I recognize your name from the kdrama post haha, so I hope you can just chill, watch some kdr...

Nadya Higgins 3F

Thank you so much for your positivity and making us feel that we're not alone! I had a great lunch and nap after my midterm :) Haha of course! This post was partially for myself too since I was feeling pretty down after the midterm. Felt like the best way to lift up both myself and others in the sa...

Nadya Higgins 3F

I'm loving the responses everyone! Glad to see so many are doing nice things for themselves, and to those who have more midterms to study for, I feel you! Don't forget to give yourself a break every now and then though!

Nadya Higgins 3F

Hello! It depends on what your friend likes, but here, have this giant list I compiled over the years that exposes how much of a kdrama nerd I am (I will bold the ones I remember really enjoying; any unbolded ones are good too! otherwise I wouldn't have watched them). Unfortunately, haven't been abl...

Nadya Higgins 3F

Yay, I'm glad it's finally done haha!

Nadya Higgins 3F

Now that we've finished the first midterm, I know a lot of us may be relieved but stressed as well, since it was a bit rough. If you didn't think you did well (myself included), don't stress and treat yourself for getting through it! We'll all have our rough patches, and it won't always be easy, but...

Nadya Higgins 3F

It depends on the week, but recently I haven't been able to study as much as I would want to since I have 3 other classes besides this one plus a part time job. I would say I spend around an average of 5 to 10 hours, but I may have to look into devoting more time, since I've been struggling a bit.

Nadya Higgins 3F

BKoh_2E wrote:Although this probably won't be tested specifically, it may be useful to know ATP hydrolysis is an exothermic reaction, and thus moves towards the reactants when exposed to heat. I believe this was briefly mentioned in the textbook.

Thanks for the tip!

Nadya Higgins 3F

there are different ways to say that products or reactants are favored, one of which is "the reaction shifts to the left/right."

Nadya Higgins 3F

Hi, I was looking through outline 1 and found one of the points we should know is of biological examples such as ATP hydrolysis and osmotic pressure. I was wondering if anyone knew where I could find this information (if it's in the textbook or lecture) or if we should do our own research? Also, it ...

Nadya Higgins 3F

I believe if a reaction needs heat, it is to break bonds. (Think from solid to liquid and liquid to gas, bonds have to be loosened and broken)

Nadya Higgins 3F

Yes, I would assume so; though I'm curious as to what others say to this as well.

Nadya Higgins 3F

I'm guessing they will be similar to last quarter, so it should still be 50 min long, and probably have around 10 - 15ish questions? You will need to take the test through Respondus and have another device set up so that you can be on a zoom call to be proctored. In the zoom call, you will have to s...

Nadya Higgins 3F

The middle number isn't for a phase change; rather it's for the energy/heat required to bring water's temperature up from 0 to 100 degrees Celsius.

Nadya Higgins 3F

I think scientific is technically preferred, but a graphing calculator is fine (they just don't want people to store info on it or program it)!

Nadya Higgins 3F

I would say just print out the periodic table and the new equation sheet found on the 14B website just in case! (It wouldn't hurt to have the 14A one as well!)

Nadya Higgins 3F

I really love Studio Ghibli films because I grew up with them. Sometimes I'll revisit some when I feel like I want something nostalgic and comforting to watch. I also do this with some Disney movies.

Nadya Higgins 3F

K is the equilibrium constant, meaning that when you find it you have to put the equilibrium concentration of products over the equilibrium concentration of reactants. Q is the concentration of products over the concentration of reactants when the reaction is not in equilibrium. So, when Q is less t...

Nadya Higgins 3F

Yes! And as a result, this will serve as a good equation to help solve for Ka or Kb if given one but you need to find the other

Nadya Higgins 3F

My guess is that we will be tested on outlines 1, 2, and part of 3!

Nadya Higgins 3F

I agree with the others! Textbook problems and UA sessions are big helps! Also make sure to gain a conceptual understanding of the topics rather than opting to just memorize whatever equations, whether that's through watching lecture, reading the textbook, or something else.

Nadya Higgins 3F

Concentration is found with the equation moles over volume. So, in the context of the problem, he divided 1.5 moles over 0.5 L to find the concentration.

Nadya Higgins 3F

That's a good question..I would assume 10^-3 is included since it's the threshold we use to determine if K is small or not; I could be wrong though! Hopefully others have some more definitive answers!

Nadya Higgins 3F

I hope to get better at time management and regain some of my motivation/focus that I had before online classes. I want to do well in my classes while not stressing out too much!

Nadya Higgins 3F

Kc or Kp is essentially products over reactants. ([P]/[R]). If you want to find the reverse reaction, you will have to flip that ratio as well, making it reactants over products ([R]/[P]). This is why when finding the equilibrium constant for a reverse reaction, you will need to find the reciprocal ...

Nadya Higgins 3F

K will not change because no matter the initial conditions, the ratio should be the same. Q will be different just because you changed the amount of product/reactant at the time, throwing the reaction out of equilibrium but it will eventually return to the value of K.

Nadya Higgins 3F

In those cases you should rely on the context of the problem and choose the one that makes more sense. For example, don't choose the one that is bigger than the initial condition.

Nadya Higgins 3F

As someone who took Lavelle's class last quarter and didn't do as well as I hoped, I found the most helpful things that I should have taken advantage of were UA sessions. I also should have focused more on practicing textbook problems because much of the information on his tests reflect the textbook...

Nadya Higgins 3F

We covered this in LS30A a bit! It's like an interaction rate; anytime something has to interact with each other they will be multiplied. For example if you have a reaction A + B <---> 2C + D then K would equal [C^2]*[D]/[A]*[B]. As you can see an A and a B have to interact with each other to form t...

Nadya Higgins 3F

I'm not too sure either; I think the earliest discussion sessions are Tuesday, which is why we haven't heard anything about TAs yet. Hopefully Dr. Lavelle will send a clarifying email today.

Nadya Higgins 3F

If the coordination compound has an overall negative charge, you have to attach -ate to the end of the transition metal.

Nadya Higgins 3F

I really enjoy listening to lo-fi mixes or instrumental versions of songs I like (from OSTs, albums, etc)!

Nadya Higgins 3F

The shorter the bond, the stronger the bond. And the stronger the bond, the weaker the acid. HF has quite the short and strong bond due to their difference in electronegativity, so it's classified as a weak acid.

Nadya Higgins 3F

This kept happening to me as well. I just kept on refreshing and re-connecting to my wifi and eventually it worked. For some reason I also found that using the UCLA VPN only worked sometimes and half the time, it felt like it made the video load slower.

Nadya Higgins 3F

Well I think with our knowledge on how to draw lewis structures when given a compound or molecule, it wouldn't be farfetched to think that may expect us to at least be able to tackle a question asking us to draw the structure of an acid. However, I think while it may be good to know, he was probably...

Nadya Higgins 3F

Ka is the value that basically tells you how much an acid will dissociate. The higher the Ka, the stronger the acid (which makes sense because if you look at how Ka is found by taking products over reactants, the H3O+ ion is in the numerator, meaning Ka and H3O+ are directly proportional) . pKa is f...

Nadya Higgins 3F

I generally just think that if you are adding a proton such as in the case of a conjugate acid, then the charge will increase by one because it's getting more positive. If you are taking a proton away such as in the case of a conjugate base, then the charge will decrease by one because it's getting ...

Nadya Higgins 3F

Does anyone know if the sections are the same? If two TAs are both reviewing the same topic will it be the same practice? I'm not sure, but I think it should be similar to UA sessions where each meeting is different depending on who is teaching it, even if the focus is the same. It probably will de...

Nadya Higgins 3F

It should be around an hour each; but I'm sure depending on the TAs or the questions asked, then times can go on longer.

Nadya Higgins 3F

Madison Muggeo 1G wrote:I did the same thing! I spelled ammine 'amine' and could not figure out why the problem kept marking the question incorrect. Glad you figured it out :)

Haha thank you! Glad to know I'm not alone on this!

Nadya Higgins 3F

I hope to spend more time drawing and finally try to learn how to embroider!

Nadya Higgins 3F

I think en is the most important to know! Other than that, it wouldn't hurt to familiarize yourself with other common ligands.

Nadya Higgins 3F

Alen_Huang_3A wrote:Try Hexamminecobalt(III) Chloride.

I think u only need 1 a for hexammine and also you spelt cobalt wrong.

Oh my gosh, thank you! It was because of the cobalt typo in my answer haha.

Nadya Higgins 3F

Hello, I've been having trouble figuring out the name of the compound [Co(NH 3 ) 6 ]Cl 3 To my understanding, ammonia is neutral so the only thing affecting the charge of the coordinate compound are the three chlorines, giving it an overall charge of 3-. This is why cobalt has (III) by it as its cha...

Nadya Higgins 3F

Points for discussion are tracked on a weekly basis by our TAs I believe. So we should be making 5 posts a week at least. Dr. Lavelle should update the discussion grade after week 10 so we can see our final discussion grade.

Nadya Higgins 3F

the number outside is the overall charge; to find the oxidation number, usually you want to find the charges of each of the outer bonded atoms and add them up. You want the charges of the outer atoms and the center atom to be equal to the overall charge, so you need to determine the charge of the ce...

Nadya Higgins 3F

Thank you this is very helpful, especially as someone who isn't able to make it to many extra sections for practice!

Nadya Higgins 3F

The textbook uses the new naming convention. However, as Dr. Lavelle mentioned in the most recent lecture, either the new way or the more common (old) way is fine. I would just keep in mind that, for example, either saying chloro or chlorido is an option, and both work fine.

Nadya Higgins 3F

I often don't have the time to go to them, but when I do, I find they really help me to understand the concepts better! Having a space to do practice problems and ask questions is always really great.

Nadya Higgins 3F

I think the best way to remember is just through practice and making sure you understand the concepts! Doing the textbook problems or watching videos on the topic always help.

Nadya Higgins 3F

Yeah, I think he meant to say tetrahedral; he probably just misspoke.

Nadya Higgins 3F

My TA recommended that we know all the shapes plus the number of bonds and lone pair associated with them. Even if some don't show up on the final, it's better knowing than not knowing!

Nadya Higgins 3F

To be honest, not much has changed and I think that has been the issue for me. My schedule doesn't permit me to go to as many UA sessions as I want and I find it hard to fit in time where I can study without distraction. I mostly take notes during lecture, and try to do the textbook problems on the ...

Nadya Higgins 3F

Lone pairs are highly repulsive and in order to make everything more stable they need to be further away from each other. In the equatorial positions they have less influence over the other bonded atoms as opposed to if they were in the axial positions.

Nadya Higgins 3F

The 2p and 2sp^2 orbitals a smaller energy gap between them than 2s and 2p because the 2sp^2 hybridized orbital is found in between the 2s and 2p orbitals. Atoms forms hybridized orbitals because it makes the resulting molecule more stable (lower potential energy) because it allows the regions of e...

Nadya Higgins 3F

Kailani_Dial_3G wrote:Hi Nadya, ethene has 2sp^2 hybridized orbitals, it does not have 2sp^3

I see, I must have misunderstood his example; I will watch that part of the lecture again. Thanks for your help!

Nadya Higgins 3F

Hi! I am also confused on the first part of your question, but I think I can explain the second part. So because the the gap between the "regular" atomic orbital space between 2p and 2s is larger than the gap between the the hybridized and the 2p then there can be no paired electrons. Hop...

Nadya Higgins 3F

I was watching today's lecture and got confused on the example of ethene. I was wondering if anyone could explain to me why ethene has sp3 orbitals when it was an example of sp2 hybridization, and also what Dr. Lavelle meant when he was talking about the energy gap and the spin-pair energy?

Nadya Higgins 3F

Q: Why does hamburger yield lower energy than steak?
A: Because it's in the ground state.

Nadya Higgins 3F

That's strange. I have no issue accessing the lectures. Maybe try restarting your browser or your computer?

Nadya Higgins 3F

You should be around 35 posts by the end of this week. The goals is to be making 5 posts a week if you want to get all 5 points for the said week (1 post = 1 point).

Nadya Higgins 3F

Thank you! Also, would it be okay to take the Chem 14BL Lab section from 11am-1:30pm on Friday even though it goes into Chem 14B's friday lecture at 1pm, since the lecture is recorded? I think that should be fine! From what I understand, the lectures will still be asynchronous like they are now, so...

Nadya Higgins 3F

I believe most of the content on Midterm 2 will be a bit more conceptual, and will not be as calculation heavy as the first. The only true calculations we have is formal charge I think.

Nadya Higgins 3F

From what I understand and what my TA said, I believe it means the same thing and many times it comes down to a matter of preference for whether you want to put s or d first. However, I'm not sure if there is a single preferred way Prof. Lavelle wants us to write it as. Also, I think electrons tend ...

Nadya Higgins 3F

Schrodinger's equation is quite complicated and we never really went into how to actually perform calculations with it. I believe just understanding it conceptually is all that matters.

Nadya Higgins 3F

I'm on a pre-med track and am currently a pre-psychobio major. Is anyone in a similar boat to me who knows what the consequences of changing to P/NP will be? What are the pros or cons?

Nadya Higgins 3F

I second this! I would love to have a playlist of the songs he uses for lectures or that he listens to regularly!

Nadya Higgins 3F

Dr. Lavelle never mentioned having to know the exact numbers and didn't go into that during lecture either, so I believe just knowing the trends is as far as we need to know. The textbook probably had the numbers and all that to be more thorough.

Nadya Higgins 3F

I think hydrogen bonding is sort of like a subset or special type of a dipole-dipole interaction. In the case of water, I feel like it's better to just think of it as hydrogen bonding though.

Nadya Higgins 3F

I think so far we have just gone over how to determine the amount of electrons to draw and where to draw them (as lone pairs or as single, double, triple bond, etc). However, while we have started to touch on attractive forces and all that, I don't think we have fully gotten into the shape of molecu...

Nadya Higgins 3F

I believe he included the lone pairs to illustrate how Na+ exerts an electrostatic attraction on the electrons surrounding Cl- causing the electrons to be pulled into the bonding region. This shows that Na+Cl- has some covalent bond character.

Nadya Higgins 3F

Double bonds are shorter and stronger because the electrons are more tightly held. This makes it harder for the bond to be broken and so double bonds are less reactive than single bonds.

Nadya Higgins 3F

Thank you Nadya! That's what I've been trying to do, I just wanted to see if I was the only one and I clearly am yikes. No problem! And also, no worries!! I felt lost with the syllabus at first too, but I guess I just kind of accepted that it's more of a loose guide than an actual manual per-say. I...

Nadya Higgins 3F

Thank you Nadya! That's what I've been trying to do, I just wanted to see if I was the only one and I clearly am yikes.[/quote] No problem! And also, no worries!! I felt lost with the syllabus at first too, but I guess I just kind of accepted that it's more of a loose guide than an actual manual per...

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