CHEMISTRY COMMUNITY

Lillian

C to D has the lowest activation energy required to perform the step.

Lillian

I quite like thermodynamics. It wasn't very easy, but it was still a fun concept to learn.

Lillian

If the a in Ea is subtext, it's referring to activation energy, I think.

Lillian

I haven't even the slightest clue as to what clubs I even want to join. I feel as though there isn't as much information about clubs online as I'd like there to be :,)

Lillian

I've applied to take an EMT course and summer sessions. I'm going to be tired, but at least I'll.... be tired...

Lillian

I'm reading Still Life With Crows right now and it's pretty good. But it's about crime (murder) so if you're squeamish I wouldn't be too keen on going for this one.

Lillian

Teti Omilana 1G wrote:The time change should be automatic!

Oh that's good to hear (I say, as I'm sitting at my desk *awake* at 4AM)

Lillian

Don't know if you'll see this, but I just hope you don't feel too alone in this. First off, I can't begin to imagine how you felt in that situation, but man has this quarter been hard for me. I had a big issue happening in the family just before finals, my CCLE stopped working and kicked me out, it ...

Lillian

Well, I can't tell you how surprised I was when Prof. Lavelle started playing Glass Animals in class. They're one of my favorite bands. Highly recommend a listen if you're into trippy music.

Lillian

Why would you be taking Chem 14CL? I thought Chem14BL came after Chem14B?

Lillian

Hannah Chang 3K wrote:
Lillian wrote:I go by the whole, "If you can do something about it, don't worry. If you can't do something about it, don't worry." Kind of helps with the whole anxiety surrounding something like this.

Nice one. I'm gonna try practicing this mindset.

HAH! I know right??

Lillian

If you pass the class, you won't be able to retake it, but honestly I wouldn't sweat it too much. Your GPA is definitely important, but it doesn't define you obviously. I would say it's more important that if you do choose to continue on the series, you do your best to do better in 14C and CL. If y...

Lillian

Adventure Time, Over The Garden Wall, Gravity Falls, Peaky Blinders :)

Lillian

I absolutely love Adventure Time, Over The Garden Wall, Gravity Falls, Avatar: The Last Airbender, and I'm trying to get into Killing Eve (still not too sure about this one).

Lillian

There's been a slight tweak so print it again just in case :)

Lillian

E naught will be zero at equilibrium, when the concentrations of the reactants and products are the same.

Lillian

n refers to the number of moles of electrons transferred. So to find it, balance the redox reactions :)

Lillian

n refers to the transfer of electrons in the process. To find it, balance the redox reactions.

Lillian

Balance the redox reactions (half-reactions then combine) and you'll see the exchange in moles.

Lillian

I think it's talking about whether the metal will spontaneously form ions or not.

Lillian

Hand-written notes are my best friend. Whenever I study, I just look back at the things I've starred or underlined and boom. I got all my review right there for me.

Lillian

Sometimes I think about food theory/chemistry and how foods that are seemingly completely different can work together very well if they just share the same compounds. I've seen some really strange combinations but they work, so hey! :)

Lillian

I feel the same way. I've been looking forward to walking this path towards what would hopefully take me to med school, but this whole situation with virtual classes has really thrown me off. It's disorienting for sure.

Lillian

I feel the same way. I've been looking forward to walking this path towards what would hopefully take me to med school, but this whole situation with virtual classes has really thrown me off. It's disorienting for sure.

Lillian

Hi, I don't think we're going to be tested on derivations of equations, so I don't have any :)

Lillian

A concentration cell wants to make the two solutions the same concentration, so on the lower concentration side (anode), the metal is oxidized to form more of the aqueous solution while the opposite happens for the high concentration side (cathode).

Lillian

Not sure... Did the study guide say anything about it?

Lillian

I'm not going to be taking a chem class spring quarter, but I have enrolled in a summer session with chem 14BL

Lillian

I go by the whole, "If you can do something about it, don't worry. If you can't do something about it, don't worry." Kind of helps with the whole anxiety surrounding something like this.

Lillian

I'd have to see with the whole virus situation and people not listening to mask mandates, but I sure would like to dorm. Planning on it once I get the vaccine.

Lillian

Bean paste stew. Mom always made it for me growing up.

Lillian

I will be doing an all nighter. /j

Lillian

I'd redo hw problems and look over the study guide once or twice.

Lillian

Oh I am not the best at this, but I just make sure to take breaks every hour or so just to catch my breath. And drink lot of water and eat snacks.

Lillian

I think you need a 50% in the class to pass with a C-, or at least that's what I've heard.

Lillian

I'd probably play it safe and use C + 273.15 = K.

Lillian

Yes, as you can apply heat and work to both open and closed systems, I think. But I think we'll be using it more commonly for closed systems anyway.
Hope this helps :)

Lillian

The n specifically refers to "number of moles." It can, however, be replaced with an m for "mass (in grams)" when using molar heat capacity. Hope this helps.

Lillian

If it's concerning a change in temperature, then no. But most other cases, probably...

Lillian

I didn't realize someone else asked this question and posted one of my own. :,)
In your case, yes. But the thing I'm unsure about is if we pull the piston our (the surroundings make the volume increase), is work positive or negative? Do we just ignore this possibility?

Lillian

When we say "Work is positive when work is done ON the system," does this mean when I pull the piston rather than push it inwards (make the volume bigger rather than smaller), the work is still positive?

Lillian

It's a ratio constant, so they cancel out.

Lillian

Use 8.314 in this case, but your best bet would be to look at the given units for the equation and see which one cancels out the units properly :)

Lillian

It doesn't really matter when the problem asks for delta temp (ONLY FOR DELTA TEMP THO... I think).
Let's say a system goes from 25 C to 30 C. The difference in temperature is 30 - 25 = 5.
When you convert the two from C to K, it looks like this: (30 + 273) - (25 + 273) = 303 - 298 = 5.

Lillian

It really depends on the wording for this kind of question, but: If you're spending energy ON the system, the work done to the system is positive. When you compress a piston on the system, YOU are spending energy to do work on the system, which means the system is receiving that energy. That means t...

Lillian

An example would be compressing a piston to decrease the volume of the system. The volume decreases, the work done TO the system is positive, and therefore the system's energy gains a net positive energy.

Lillian

K (Kelvin) is a measure of temperature, just like Celsius or Fahrenheit. We most commonly use Celsius and Kelvin, as the only difference between the two is that Kelvin = Celsius + 273.

Lillian

A closed system would look like a sealed beaker with no insulation. It can be heated and compressed with a piston (therefore changing the energy of the system via the surroundings), but nothing physical can be added to it (other elements or substances). We can observe the effects of putting in energ...

Lillian

Jaclyn Dang 3B wrote:I heard that it was really manageable since being online. I am not sure however if there are synchronous meetings.

I feel like it wouldn't be as fun though. Are they usually hard in person?

Lillian

I haven't taken it yet, but next quarter I'm planning on taking chem 14BL, chem 14C, ls7b, and potentially a class for my minor. I heard labs are a lot easier online since you don't need to do the experiment yourself, so I think you're fine taking multiple STEM courses. :) Oh this sounds like a goo...

Lillian

Hello. I have a hard time studying when I'm feeling down, and sometimes it feels like a mountain bearing down on my chest whenever I have stuff to catch up on. How do you guys deal with the stress/workload when you might be in this kind of mood?

Lillian

What's H204?
Depends. If you're thirsty, drinking. If you're dirty, washing.

Lillian

He mentioned the processes involved in acid rain and the recent spike in carbon dioxide in our atmosphere. Not sure if there's more..

Lillian

Halle Villalobos 3C wrote:Hi! I believe there is a link to a google drive test bank folder in the class GroupMe that has past exams. Good luck with finals!

Ooohh! Noted!

Lillian

505598869 wrote:Textbook problems are my best friends at the moment... my only friends...

I feel that... I haven't been able to meet up with my friends >:,)

Lillian

I'm going to sleep until my organs fail, obviously.

Lillian

I feel like Lavelle did a lot for us this quarter, especially in this situation, but I can't help but sometimes wish for more, ya know? I wish the classes were in person because the videos do NOT help me to focus at all. I did get through them, but man, was it difficult to focus without a live lectu...

Lillian

You look at the electronegativity in each of the atoms (Cl are the more electronegative ones), then determine where the charge is being pulled. If the atom is uneven like it is in 1, the less the pull cancels out, leading to a larger dipole moment :) Hope this helps

Lillian

I would love to hear professor Lavelle's input on this. I've been thinking the same thing haha. Ey it might not be the best idea to have your name as your student ID. It's kinda important, man. My bad, didn't notice that I had it as that. Does UID fraud actually happen? You're probably good lolol. ...

Lillian

Make sure you stand up and stretch every 20-30 minutes when you study! Give yourself enough breaks so that your brain has time to process the information as you pick it up. It's really good for both physically and mentally (we need as much of that during this pandemic lol).

Lillian

Happy late Thanksgiving hehe! My family loves going on trips to the mountains to hike and chill, although this year was a bit different... I did eat a lot of food and play lots of Animal Crossing so I'm pretty content :DD

Lillian

I think it's a war crime to not mention Adventure Time and Over the Garden Wall. *chef's kiss*
Also if you want a really good but extremely gory (to the point where you'll be surprised it even aired) show, watch Hannibal.

Lillian

305311217 wrote:I would love to hear professor Lavelle's input on this. I've been thinking the same thing haha.

Ey it might not be the best idea to have your name as your student ID. It's kinda important, man.

Lillian

It walks on the line between blurry and clear and I get distracted by it so I have to skip back a lot to see what he said lol

Lillian

I've mostly been reviewing the problems like a lot of other people, but I think skimming through the lectures is a pretty good way to review as well :)

Lillian

I have been reviewing problems in the book and on Sapling. Are there any specific Youtube channels anyone can recommend that effectively review this course's material? Personally, I watch organic chemistry tutor on youtube when I need clarification on concepts! The videos are very detailed, clear, ...

Lillian

Adding onto this, I ended up figuring this out, but I'm still confused about the exact number, I counted the atoms most likely to form a Hydrogen bond but that number was less than the number I ended up getting. The exact amount is 8 I'm pretty sure. For each hydrogen atoms, the oxygen in a water m...

Lillian

Follow Dr. Lavelle! The arrow should be pointing towards the negative dipole, because it indicates where electrons are being pulled. What determines the negative dipole again? The more electronegative atom has the negative dipole because it pulls electrons toward itself more! Electronegativity incr...

Lillian

Adding onto this, I ended up figuring this out, but I'm still confused about the exact number, I counted the atoms most likely to form a Hydrogen bond but that number was less than the number I ended up getting. The exact amount is 8 I'm pretty sure. For each hydrogen atoms, the oxygen in a water m...

Lillian

Bond character refers to how strong the attraction is (how short the bond length is). Even if you don't know, you can assume that, from the chart they give you, the C-N and C-O bonds aren't "overwhelmingly" strong and the C=N and C=O bonds are pretty short. From this you can assume that th...

Lillian

SashaAnand3G wrote:Follow Dr. Lavelle! The arrow should be pointing towards the negative dipole, because it indicates where electrons are being pulled.

What determines the negative dipole again?

Lillian

I wasn't really clear on this from the lectures, but what is the significance of bond length in determining the stability of structures? And what does a shorter bond length really entail?

Lillian

Do we need to know the details of the difference between sigma, pi, and delta bonds?
Or just this?:
single bond = 1 sigma
double bond = 1 sigma 1 pi
triple bond = 1 sigma 2 pi
quadruple bond = 1 sigma 2 pi 1 delta

Lillian

This is pretty off-topic, but I think I may have missed some information during the discussions... I don't know where to find the given periodic table and equations sheet to print. Can someone point me towards it? Thanks :) You can find it on the tops of the class website under "Constants and ...

Lillian

They are on Dr. Lavelle's website, but I'll provide you direct links to make it easier: Constants and Equations: https://lavelle.chem.ucla.edu/wp-content/supporting-files/Chem14A/constants_equations.pdf Periodic Table: https://lavelle.chem.ucla.edu/wp-content/supporting-files/Chem14A/Periodic_Table...

Lillian

This is pretty off-topic, but I think I may have missed some information during the discussions... I don't know where to find the given periodic table and equations sheet to print. Can someone point me towards it? Thanks :)

Lillian

Would the middle zeros have significance? like in 202.

Lillian

Is there any way to search the contents of a post? For example if there aren't any posts on a certain problem that I can find with the subject name, can a search direct me to the next closest thing?

Lillian

To my knowledge, orbitals are more representations of where the electron can be found at any given time. For example, with an s orbital, there's a sphere of space where the electron can be found, whereas with the p orbital it's more of a peanut shape. Is that all we need to know conceptually as far...

Lillian

The negative ion would have a larger radius because in this case, the nuclear charge stays the same (if they're the same element). The only thing that would be changing is the number of electrons, meaning the radius would be bigger. I understand the size of the radius correlating with whether it is...

Lillian

What exactly determines the strength of an acid/base? Didn't really understand if there was a concept that I needed to know for this or there was an equation to determine this.

Lillian

Left and down = bigger radius.
The rest, I memorized as is... I do hope there's a better way than this lol

Lillian

The fluorine atom has a higher number of protons in its nucleus (meaning there is a higher charge that attracts electrons). Because of this, the attraction would be higher :)

Lillian

The negative ion would have a larger radius because in this case, the nuclear charge stays the same (if they're the same element). The only thing that would be changing is the number of electrons, meaning the radius would be bigger.

Lillian

With this specific set of ions, we can see that all of them have the same number of total electrons. The only difference is their nuclear mass and charge. The more protons the atom has, the more attraction it holds on the electrons, which brings them closer to the nucleus (like a magnet). :D Hope th...

Lillian

I'm guessing the midterm scores will be released later this week. Maybe. No idea of knowing for sure with college.

Lillian

I've been wondering the same. How would we compute the variables, which variables would be given, and where would we see this equation being used and what for?

Lillian

Do you know when the participation points are recorded? Are they just at midnight on Sunday?

Lillian

Q: Wanna hear a chemistry joke?
A: Na.

Lillian

You will definitely need to know it for the midterm, but I wouldn't stress too much over it to the point of not studying for other topics. It's only one topic out of many we've covered so make sure that you know the basics of it I guess.

Lillian

Physically, it is impossible for an electron to reach n = infinity. As long as there is a "distance" between an electron and an atom, there will be some attraction, though it would be EXTREMELY small. So unless there is a way to reach a length of "infinity" between an atom and an...

Lillian

For something like a photon, the intensity would refer to the the number of photons sent at a target or in a certain direction. The frequency would refer to how many crests or troughs pass through a certain point in a wave. The amplitude, just in case, refers to the height of the crest or trough.

Lillian

Black Body Radiation is not on the midterm. He said in one of the lectures that it wouldn't be on the test, nor is it part of the curriculum (I think).

Lillian

In addition to offsetting the electron's velocity, it could also interact as in bind with the electron, absorb the energy of the electron, pull it in its direction, etc. It would directly affect the experiment's results.

Lillian

Calculate the energy of the proton, subtract the kinetic energy of the election from the energy of the proton, then you have the threshold energy :))))

Lillian

The test'll be in multiple choice anyway, but you'd adjust the answer to match the question.

eg.) How many nm does the electron travel?
answer: ____nm

eg.) How many m does the electron travel?
answer: ____m

Lillian

I think maybe the electron wouldn't really move from the surface, but it would still be physically separated from the other atoms/electrons (it wouldn't be bound). Then again, that's a pretty rare scenario, for the energy of the photon to match the threshold energy exactly haha :DD

Lillian

For me, it's all about doing the assigned problems and maybe even going out of your way to look for example problems from different sources (if you can). Chemistry's all about problem solving and learning the concepts as you go along. Though, for the tests Lavelle will assign, I'd recommend really f...

Lillian

I have been looking up prices for webcam on amazon but all of them are above $35 and my budge is around $25. Anybody know where I can find a webcam for cheap price? if you purchased one, can you drop the link for the website below This is a 1080 HD camera you can get off of Amazon: https://www.amaz...

Lillian

I mean, the textbook problems can only help, right?

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