Search found 102 matches
- Sat Mar 13, 2021 7:26 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Gibb's Free Energy vs Enthalpy
- Replies: 4
- Views: 257
Re: Gibb's Free Energy vs Enthalpy
When a reaction's gibbs free energy is negative, then the reaction in question is spontaneous. This can be explored through the equation delta G nought = delta H nought - T * delta S nought. For example, a large positive entropy value can overcome a positive enthalpy. Remember from the kinetics sect...
- Sat Mar 13, 2021 7:22 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Chemistry Community Posts
- Replies: 10
- Views: 529
Re: Chemistry Community Posts
I believe they will stay up, as you can search and find various old posts from years past. It's like a time capsule of sorts.
- Sat Mar 13, 2021 7:21 pm
- Forum: Zero Order Reactions
- Topic: zero order
- Replies: 47
- Views: 1690
Re: zero order
For a zero order reaction, the rate is independent of the concentration of the reactant.
- Sat Mar 13, 2021 7:20 pm
- Forum: Student Social/Study Group
- Topic: Equations for the Final
- Replies: 5
- Views: 329
Re: Equations for the Final
Conceptually, it's helpful to remember that delta G nought is equal to work max as well as kforward/kreverse=K
- Sat Mar 13, 2021 7:19 pm
- Forum: Student Social/Study Group
- Topic: General tips/hints
- Replies: 5
- Views: 333
Re: General tips/hints
I agree with Hayden, it really helps to look over practice problems and practice applying the equations so you can understand what equation goes with what concept.
- Sun Mar 07, 2021 4:36 pm
- Forum: General Science Questions
- Topic: Final Exam
- Replies: 39
- Views: 1694
Re: Final Exam
Lavelle organizes review sessions throughout Week 10 so there is plenty of opportunities to review. For a study guide, the textbook problems listed on his website are a big help as well as the sections covered in the textbook.
- Sun Mar 07, 2021 4:32 pm
- Forum: Student Social/Study Group
- Topic: What do you miss / What are you looking forward to?
- Replies: 92
- Views: 7871
Re: What do you miss / What are you looking forward to?
I really miss the atmosphere. Just walking to and from class. The little things really made UCLA feel so special. Sure there were big things that made it great, too, don't get me wrong. But, the feeling of UCLA truly was something and I am excited to be back.
- Sun Mar 07, 2021 4:30 pm
- Forum: Student Social/Study Group
- Topic: Chem 14C
- Replies: 17
- Views: 815
Re: Chem 14C
I've heard that some people who struggled with other parts of chemistry conceptually sometimes enjoy 14C more since its a bit different. I've heard it compared to preferring geometry or algebra. So it may appear daunting but when we get into it, you may really enjoy it. We'll find out!
- Sun Mar 07, 2021 4:24 pm
- Forum: Student Social/Study Group
- Topic: Moving to Westwood soon. Which restaurants should I visit?
- Replies: 45
- Views: 2326
Re: Moving to Westwood soon. Which restaurants should I visit?
These are some great suggestions. I can't wait to go back to UCLA and give some of these a try.
- Sun Mar 07, 2021 4:23 pm
- Forum: Student Social/Study Group
- Topic: How do you deal with burnout?
- Replies: 144
- Views: 12719
Re: How do you deal with burnout?
To help with burnout, I like to go on walks or runs. Being outside and exercising can be a great help. Also leaving wherever you work for just a little can help as well.
- Sun Feb 28, 2021 8:28 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Chemistry Community Points
- Replies: 24
- Views: 964
Re: Chemistry Community Points
Like others have stated, you cannot earn more than the 50 points (5 points per week) for Chemistry Community. You just get 5 points a week x 10 weeks!
- Sun Feb 28, 2021 8:27 pm
- Forum: Student Social/Study Group
- Topic: Fave movie/show
- Replies: 67
- Views: 4144
Re: Fave movie/show
These are some solid recommendations. Breaking Bad has a little chemistry in it, but not the good chemistry we have here in the 14 series. I have to recommend the classic show Psych! It's on amazon prime video and probably hulu.
- Sun Feb 28, 2021 8:25 pm
- Forum: *Organic Reaction Mechanisms in General
- Topic: K meaning
- Replies: 29
- Views: 2016
Re: K meaning
The Boltzmann constant, k, is on our equation sheet! it is equal to 1.38x10^-23 J/K. Be careful not to confuse it with K, the equilibrium constant for a reaction.
- Sun Feb 28, 2021 8:17 pm
- Forum: Balancing Redox Reactions
- Topic: states of matter
- Replies: 58
- Views: 2065
Re: states of matter
Yes, there's a question or two where you need to include the phases. It is interesting as there are some problems that have it as optional. I wonder why sapling decided to structure it this way.
- Sun Feb 28, 2021 8:16 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: E vs E naught
- Replies: 36
- Views: 1437
Re: E vs E naught
E naught is a lot like G naught from thermodynamics. Its the value of E at standard conditions. At nonstandard conditions (E), we have to convert using an equation.
- Sun Feb 21, 2021 3:43 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: State function?
- Replies: 36
- Views: 1250
Re: State function?
E depends on the path taken, so it would not be a state function. You are not able to compare the final and initial states like you would with a state function.
- Sun Feb 21, 2021 3:41 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Tips for Concentrating during a test
- Replies: 31
- Views: 1067
Re: Tips for Concentrating during a test
Definitely a good strategy is to arrange some kind of quiet time or you time before the test, so that you enter the exam with a clear mind. Test stress can hurt your focus and performance on the test, so don't over think it.
- Sun Feb 21, 2021 3:39 pm
- Forum: Student Social/Study Group
- Topic: Has anyone taken Chem 20L before?
- Replies: 3
- Views: 392
Re: Has anyone taken Chem 20L before?
I have a friend taking 20L and it sounds fairly similar to 14BL but perhaps a little bit more rigorous and separated from the biological context found in the 14 series.
- Sun Feb 21, 2021 3:38 pm
- Forum: Student Social/Study Group
- Topic: Classes for next quarter?
- Replies: 165
- Views: 12165
Re: Classes for next quarter?
I'm going to be taking 14C and an upper div, but I am not so certain for another class since stats 13 and physics 5C filled up really quickly.
- Sun Feb 21, 2021 3:37 pm
- Forum: Administrative Questions and Class Announcements
- Topic: struggling
- Replies: 73
- Views: 3389
Re: struggling
I always recommend going to the UA sessions it can help give you more advanced practice and help reinforce concepts as well as open up the opportunity to ask questions in a pseudo-in-person sort of fashion.
- Sun Feb 14, 2021 2:06 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: R Constant
- Replies: 91
- Views: 4972
Re: R Constant
You are correct in assuming that you use .08206 with atm, the other value is for use with energy or work (notice it has joules in its units). Like with most concepts in this class, units are very important and can be the deciding factor for which values are used.
- Sun Feb 14, 2021 2:04 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: temperature
- Replies: 32
- Views: 1137
Re: temperature
It will depend on the problem in question and the units that are given. Sometimes, you can get away with keeping celcius if a change in temperature is needed (since the relative difference will be the same regardless of which unit). But other times call for Kelving to be used to do a difference in u...
- Sun Feb 14, 2021 2:02 pm
- Forum: Student Social/Study Group
- Topic: Chem 14BL Workload
- Replies: 22
- Views: 1126
Re: Chem 14BL Workload
I would say 14BL is heavily dependent on your lab group and TA, as the workload can be very manageable with a strong group that communicates well. If you can organize well, 14Bl should be more than manageable.
- Sun Feb 14, 2021 2:01 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Kelvin conversion
- Replies: 40
- Views: 2643
Re: Kelvin conversion
As everyone is citing, the conversion is +273.15 to the C value. thats why we see 298 K so often (its 25 C or room temperature).
- Sun Feb 14, 2021 1:59 pm
- Forum: Student Social/Study Group
- Topic: Song From Today's Lecture?
- Replies: 6
- Views: 534
Re: Song From Today's Lecture?
If there isn't a Lavelle Spotify playlist, somebody should make one! A collection of the 14 series greatest hits.
- Sun Feb 07, 2021 3:28 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Chem Community Grade Error
- Replies: 15
- Views: 602
Re: Chem Community Grade Error
As others have stated, Lavelle factored in this week as well as the previous weeks but we have till today at midnight to get the 5 points for this week so nothing to worry about. It will be updated later on in the quarter :)
- Sun Feb 07, 2021 3:27 pm
- Forum: Student Social/Study Group
- Topic: Chemistry Community Posts
- Replies: 12
- Views: 592
Re: Chemistry Community Posts
I think the lower number does not factor in multiple replies to the same post tree, while the higher number does.
- Sun Feb 07, 2021 3:25 pm
- Forum: Student Social/Study Group
- Topic: Study routine.
- Replies: 51
- Views: 2151
Re: Study routine.
My best resources have definitely been practice problems and the UA sessions. Someone posted a very useful study guide that briefly summed up each of the core concepts from each section in the textbook.
- Sun Feb 07, 2021 3:22 pm
- Forum: Student Social/Study Group
- Topic: Book Recommendations
- Replies: 135
- Views: 11601
Re: Book Recommendations
I have been reading Crime and Punishment for a long time (it's a bit boring in parts) but it's a very interesting book conceptually. Slaughterhouse Five and Fahrenheit 451 are both phenomenal books and I cannot recommend them enough--the latter of which is loosely tied to the thermodynamics of our c...
- Sun Feb 07, 2021 3:19 pm
- Forum: Student Social/Study Group
- Topic: Identifying Dr. Lavelle's Music
- Replies: 15
- Views: 766
Re: Identifying Dr. Lavelle's Music
i always wondered what Lavelle decided to play in class. They sounded so familiar but I couldn't place any of the sounds.
- Sun Jan 31, 2021 5:42 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: polyprotic acids
- Replies: 10
- Views: 547
Re: polyprotic acids
t=Thank you for asking this question! I was wondering when we were supposed to ignore the effect of the second or third ka values.
- Sun Jan 31, 2021 5:40 pm
- Forum: Ideal Gases
- Topic: Chem BL
- Replies: 107
- Views: 6982
Re: Chem BL
I am taking 14BL this quarter but there is not too much overlap at the moment. I would say you could take this course next quarter or later if need be.
- Sun Jan 31, 2021 5:38 pm
- Forum: Student Social/Study Group
- Topic: Go treat yourself after MT1!
- Replies: 75
- Views: 3938
Re: Go treat yourself after MT1!
Thank you for this very kind post! I think it is very important to have some time to relax and focus on your own health. We're almost at the halfway point of the quarter so we should be proud of ourselves.
- Sun Jan 31, 2021 5:36 pm
- Forum: Administrative Questions and Class Announcements
- Topic: 14C?
- Replies: 23
- Views: 795
Re: 14C?
I plan on taking 14 C next quarter, but you bring up a good point. The content may not stick through the summer break, but I believe this may just translate to helpful review.
- Sun Jan 31, 2021 5:34 pm
- Forum: Administrative Questions and Class Announcements
- Topic: midterm
- Replies: 16
- Views: 485
Re: midterm
Based off of last quarter, I would say it takes about a week for grades to come out.
- Sun Jan 24, 2021 4:55 pm
- Forum: Student Social/Study Group
- Topic: CHEM 14B Midterm 1 Notes
- Replies: 23
- Views: 1043
Re: CHEM 14B Midterm 1 Notes
Thank you! That's really kind of you to share. Good luck studying!
- Sun Jan 24, 2021 4:55 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Increase in Pressure
- Replies: 31
- Views: 661
Re: Increase in Pressure
I believe this would only be for gases rather than aqueous substances. Changing the pressure would only affect the moles of gas.
- Sun Jan 24, 2021 4:53 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Periodic Tables on Midterm
- Replies: 23
- Views: 751
Re: Periodic Tables on Midterm
Although the test is not open note or open book, Dr. Lavelle has an equation sheet and periodic table on his website that we should have printed out for the midterms and final.
- Sun Jan 24, 2021 4:52 pm
- Forum: Phase Changes & Related Calculations
- Topic: Define Phase Change
- Replies: 78
- Views: 4746
Re: Define Phase Change
A phase change is when a substance changes from one state of matter to another (gas to liquid, solid to liquid, etc.). These occur at the melting point and boiling point, for example. These are the temperatures where such phase changes can occur.
- Sun Jan 24, 2021 4:49 pm
- Forum: Phase Changes & Related Calculations
- Topic: H and q
- Replies: 47
- Views: 1494
Re: H and q
Q is for heat and H is for enthalpy!
- Sun Jan 17, 2021 3:36 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: q vs k
- Replies: 62
- Views: 2320
Re: q vs k
Yeah Q will become K, Q is indeed the value when not at equilibrium. Q wants to become closer and closer to K in order to reach equilibrium.
- Sun Jan 17, 2021 3:34 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: shifts left or right
- Replies: 23
- Views: 977
Re: shifts left or right
Shifting to the right means that the products are favored (more will be produced to fit the equilibrium) while shifting to the left means the reactants are favored (again more will be produced). It can helpful to think of the products being on the right side of the chemical equation while the reacta...
- Sun Jan 17, 2021 3:31 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Approximations
- Replies: 4
- Views: 198
Re: Approximations
The key point that leads to us being able to approximate is that .20 is so much larger than 10^-4 (relatively speaking) that the result will be just about .20 after the subtraction. It's less that x is close to zero and more that the relative operation is not impactful on the initial quantities.
- Sun Jan 17, 2021 3:28 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Amphiprotic
- Replies: 8
- Views: 300
Re: Amphiprotic
Amphiprotic molecules can act as either a proton acceptor or donor (bronsted-lowry base or acid). It's a similar term to amphoteric but specific to proton acceptance and donation.
- Sun Jan 17, 2021 3:25 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterms
- Replies: 24
- Views: 916
Re: Midterms
I'm pretty sure things will be slightly different this quarter and will be during lecture time instead of discussion section. I asked my TA about it and he told us that the logistics are still being ironed out. We will find out for sure soon.
- Sun Jan 10, 2021 7:19 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Units
- Replies: 27
- Views: 826
Re: Units
The preferred unit will be atm! You should not give an answer in moles per liter as that would be the unit for concentration rather than pressure. You can easily convert between the two as Dr. Lavelle taught in lecture.
- Sun Jan 10, 2021 7:17 pm
- Forum: Ideal Gases
- Topic: Units for Pressure
- Replies: 41
- Views: 2330
Re: Units for Pressure
We will be using atm. As Dr. Lavelle stated in lecture, 1 bar is very close to 1 atm, so for our purposes we can just use atm.
- Sun Jan 10, 2021 7:14 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Sapling homework due date
- Replies: 14
- Views: 627
Re: Sapling homework due date
Thanks for clarifying that the homework is due next Sunday 1/17! Out of curiosity, does anyone know if week 2 homework also be due that day?
- Sun Jan 10, 2021 7:11 pm
- Forum: Ideal Gases
- Topic: Advice on how to navigate Chem Community
- Replies: 17
- Views: 769
Re: Advice on how to navigate Chem Community
I heavily rely on the "Quick links" tab on the top left to navigate chemistry community, from there you can best explore the newest posts and the differing topics you may need help in or what to help someone out in.
- Sun Jan 10, 2021 7:09 pm
- Forum: Student Social/Study Group
- Topic: Comfort Movies
- Replies: 168
- Views: 21738
Re: Comfort Movies
I've always been a big star wars guy, so any of the original three help me unwind. But I don't usually like having movies or tv shows play in the background while I work or study; I feel like I end up getting easily distracted.
- Sat Dec 12, 2020 3:25 pm
- Forum: Student Social/Study Group
- Topic: Study music
- Replies: 59
- Views: 5975
Re: Study music
I listen to a lot of classical music for studying and doing work. Study's tend to say it's conducive to a good working environment. Also, apparently listening to new and different songs is beneficial!
- Wed Dec 09, 2020 4:41 pm
- Forum: Conjugate Acids & Bases
- Topic: Amphoteric
- Replies: 11
- Views: 457
Re: Amphoteric
I think in terms of what we will be exposed to in this course, we can determine if something is amphoteric based on what it is being exposed to. The outcome can tell us if it is amphoteric. I believe it is helpful know some of the most common ones, such as water.
- Wed Dec 09, 2020 4:38 pm
- Forum: Hybridization
- Topic: Determining Hybridization
- Replies: 4
- Views: 181
Re: Determining Hybridization
Look at the areas of electron density! So that's bonds and lone pairs. Keep in mind that double and triple bonds only count as one area of electron density, they don't increase the count. That's why you can have a double bond and have trigonal planar instead of tetrahedral. In this case, it would be...
- Wed Dec 09, 2020 4:35 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Naming on Final
- Replies: 9
- Views: 589
Re: Naming on Final
It seems like the best strategy is to memorize the most common ones and more specifically those within the textbook problems.
- Wed Dec 09, 2020 4:33 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Week 10 Review Sessions - Recorded?
- Replies: 7
- Views: 400
Re: Week 10 Review Sessions - Recorded?
It seems like the review sessions depend on the UA and the format, as the one I attended was not recorded.
- Sun Dec 06, 2020 1:59 pm
- Forum: Administrative Questions and Class Announcements
- Topic: 14B and 14BL
- Replies: 13
- Views: 770
Re: 14B and 14BL
I am going to be taking them together, though it is totally acceptable to do them at separate times like 7C and 23L. At the end of the day, it's more about what works for you and your schedule.
- Sun Dec 06, 2020 1:56 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final
- Replies: 21
- Views: 722
Re: Final
As others have stated, it will be pretty much the same as our past two midterms. The final will be 30 questions that are each 6 points, however.
- Sun Dec 06, 2020 1:55 pm
- Forum: Naming
- Topic: Naming Practice
- Replies: 4
- Views: 314
Re: Naming Practice
Thank you so much! Good luck studying!
- Sun Dec 06, 2020 1:54 pm
- Forum: Lewis Structures
- Topic: Angles of Bonding Pairs
- Replies: 8
- Views: 418
Re: Angles of Bonding Pairs
Emily and Serena both had solid answers and covered much of what I was thinking. It's important to know the base bond angles (180, 120, 109.5) and where they come from, but the effect of lone pairs doesn't need to be memorized quantitatively (i.e. just know that bond angles will be smaller due to th...
- Sun Dec 06, 2020 1:50 pm
- Forum: Student Social/Study Group
- Topic: Final Exam Study Tips
- Replies: 48
- Views: 2265
Re: Final Exam Study Tips
The best place to start is 100% the textbook problems. They best reflect what's gonna be covered on the test, also look into going to some of these review sessions that Dr. Lavelle has planned.
- Sun Nov 29, 2020 2:30 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Outlines for the Final
- Replies: 11
- Views: 584
Re: Outlines for the Final
Yes we are in the process of completing or will complete learning about these two outlines. As others have stated, they are relatively shorter in comparison to the outlines on the past two midterms.
- Sun Nov 29, 2020 2:28 pm
- Forum: General Science Questions
- Topic: Grade Breakdown
- Replies: 35
- Views: 1997
Re: Grade Breakdown
There was similar post about this, and it seems the consensus is all over the place. The syllabus does not give an exact breakdown and there are disagreements over them. I would say not to worry too much about the numbers and focus on doing your best!
- Sun Nov 29, 2020 2:26 pm
- Forum: Student Social/Study Group
- Topic: How to study for class
- Replies: 30
- Views: 1123
Re: How to study for class
As with the consensus here, the textbook problems are very helpful, though the textbook can be a bit greater in scale at times. Lavelle's lectures and videos online can be greatly helpful in understanding the concepts, while the textbook problems help with their application.
- Sun Nov 29, 2020 2:24 pm
- Forum: Administrative Questions and Class Announcements
- Topic: grading
- Replies: 11
- Views: 594
Re: grading
Every class does grade distributions differently, so i am not sure what the points will translate to. I was also curious about the 50% and C- thing on the syllabus. If I recall correctly, the syllabus does not say the percentages needed for each level of grade either. Some classes have A+ as only ov...
- Sun Nov 29, 2020 2:22 pm
- Forum: Student Social/Study Group
- Topic: How have your study habits changed?
- Replies: 45
- Views: 1645
Re: How have your study habits changed?
Certainly, the one constant so far has been doing the textbook problems. Although, I too have revamped how I have been taking notes in class. Another important strategy I have adopted is to ask myself if I can explain each topic and see if I really can define key terms. It helps me better understand...
- Sun Nov 22, 2020 4:22 pm
- Forum: General Science Questions
- Topic: # of chem posts
- Replies: 27
- Views: 1460
Re: # of chem posts
We need 35 posts by tonight at midnight. Each week has a requirement of 5 posts, so 40 next week, then 45 for week 9, and finally 50 by week 10.
- Sun Nov 22, 2020 4:18 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Lectures through Thanksgiving
- Replies: 7
- Views: 430
Lectures through Thanksgiving
Hey all, I was just wondering if there will be lectures and discussion on wednesday and/or friday. Some classes have cancelled both, though I am unsure what 14A's plan is for this upcoming week.
- Sun Nov 22, 2020 4:15 pm
- Forum: Student Social/Study Group
- Topic: Winter 2021 Classes
- Replies: 20
- Views: 916
Re: Winter 2021 Classes
12 is the minimum! That's what you need to be a full-time student. Don't worry about this too much, everything will work out!
- Sun Nov 22, 2020 4:11 pm
- Forum: Student Social/Study Group
- Topic: Study Tips for Final Exam
- Replies: 57
- Views: 2452
Re: Study Tips for Final Exam
I would say textbook problems and the UA worksheets are our best bet for studying. They're solid resources and help build understanding. I definitely think I will be attending more UA sessions in preparation for this exam.
- Sun Nov 22, 2020 4:10 pm
- Forum: Student Social/Study Group
- Topic: Exercising Our Minds and Bodies
- Replies: 120
- Views: 14556
Re: Exercising Our Minds and Bodies
I've been running a few miles or so each week, nothing too crazy. It's nice to go out to trails if possible.
- Tue Nov 17, 2020 1:36 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Chem 14BL and Chem 14B
- Replies: 6
- Views: 181
Chem 14BL and Chem 14B
For enrollment, do we need to take both these courses at the same time, or is it like LS 7C and LS23L where we have the option to take 7C first and 23L later on?
- Tue Nov 17, 2020 1:33 pm
- Forum: Student Social/Study Group
- Topic: Midterm 2 Content
- Replies: 2
- Views: 112
Re: Midterm 2 Content
Thank you, Cassidy! I just wanted to double check. Good luck studying!
- Mon Nov 16, 2020 7:48 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Midterm 2 Textbook Topics
- Replies: 3
- Views: 90
Re: Midterm 2 Textbook Topics
It is a good idea to check and see if you can define each of the bullet points as Simer said. Sometimes, we think we know certain topics or ideas, but it can be difficult to explain. If we can explain them effectively, then we have a much better understanding of the topic and it will show on the test.
- Mon Nov 16, 2020 7:41 pm
- Forum: Student Social/Study Group
- Topic: Chemistry Among Us
- Replies: 43
- Views: 1967
Re: Chemistry Among Us
Are you going to continue this series of posts? Many of us--myself included--would like to know where you're going with this.
Also, I would call out green.
Also, I would call out green.
- Mon Nov 16, 2020 7:38 pm
- Forum: Student Social/Study Group
- Topic: Midterm 2 Content
- Replies: 2
- Views: 112
Midterm 2 Content
Just to confirm, the last lecture that will have content on Midterm 2 is Wednesday from last week, right? I just want to be certain before going into the test.
- Mon Nov 16, 2020 7:35 pm
- Forum: Administrative Questions and Class Announcements
- Topic: MT 2 Material
- Replies: 4
- Views: 150
Re: MT 2 Material
Based on your question, it seems you dealing with Chem 14A material though you posted in the Chem 14B section. Just a reminder to take note of that, you'll probably get more answers from fellow 14A students if you post in the right class section.
- Mon Nov 16, 2020 7:32 pm
- Forum: Student Social/Study Group
- Topic: Midterm 2 content
- Replies: 20
- Views: 707
Re: Midterm 2 content
As many have already stated, lewis structures is a key focus for this section. It would be helpful to do the sapling textbook problems to practice making these. I believe this midterm stops content-wise at hydrogen bonding.
- Sun Nov 08, 2020 6:35 pm
- Forum: Trends in The Periodic Table
- Topic: # of electrons
- Replies: 23
- Views: 606
Re: # of electrons
Each element has a number of electrons equal to its atomic number. However, it can have more or less depending on if it is an ion or not (loses as a cation (+), gains as an anion (-)).
- Sun Nov 08, 2020 6:31 pm
- Forum: Student Social/Study Group
- Topic: Lecture on Veteran's Day
- Replies: 10
- Views: 294
Lecture on Veteran's Day
Will there be a lecture posted this Wednesday? Just checking to see as it's Veteran's Day.
- Sun Nov 08, 2020 6:27 pm
- Forum: Electronegativity
- Topic: Noble Gases
- Replies: 40
- Views: 12411
Re: Noble Gases
As many have already stated, Noble Gases are exempt from the electronegativity trend, as they already have a full octet and are within the most stable position.
- Sun Nov 08, 2020 6:25 pm
- Forum: Student Social/Study Group
- Topic: Chemistry Among Us
- Replies: 43
- Views: 1967
Re: Chemistry Among Us
I'm heading to reactor. Not gonna risk it with Green
- Sun Nov 08, 2020 6:15 pm
- Forum: Student Social/Study Group
- Topic: Favorite TV shows
- Replies: 277
- Views: 33381
Re: Favorite TV shows
Mr. Robot is ridiculously good. It has some of the best writing on TV ever, great performances from the cast, and spectacular direction.
- Sun Nov 01, 2020 8:01 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Writing Electronic Configurations
- Replies: 8
- Views: 211
Re: Writing Electronic Configurations
It will depend on the problem asked! Some will ask for the full configuration and other won't. If they don't, it is easiest to refer to the latest noble gas and build your configuration from there.
- Sun Nov 01, 2020 7:59 pm
- Forum: Properties of Light
- Topic: Is c always the speed of light?
- Replies: 92
- Views: 4744
Re: Is c always the speed of light?
Yes, the constant c will remain a constant 2.99792 x 10^8 m/s. c will always refer to the speed of light for the purposes of our classes (as far as I am aware).
- Sun Nov 01, 2020 7:56 pm
- Forum: Trends in The Periodic Table
- Topic: Electron Affinity
- Replies: 4
- Views: 179
Re: Electron Affinity
Electron affinity is the change in energy when a negative ion is formed (an electron joins a neutral atom). For example, it looks at the change in energy from an F atom to an F^-1 atom.
- Sun Nov 01, 2020 7:02 pm
- Forum: Student Social/Study Group
- Topic: Halloween!!!
- Replies: 73
- Views: 2961
Re: Halloween!!!
I took a mental day and watched The Addams Family with some friends! I probably should have done some more homework but it was nice to have a day off.
- Sun Nov 01, 2020 7:00 pm
- Forum: Lewis Structures
- Topic: Octet Rule
- Replies: 12
- Views: 427
Re: Octet Rule
The first four elements do not abide by the octet rule (H, He, Li, Be) as they only fill the 1s and 2s subshells.
- Sun Oct 25, 2020 4:47 pm
- Forum: SI Units, Unit Conversions
- Topic: units to know for midterm
- Replies: 11
- Views: 694
Re: units to know for midterm
On the constants and equations worksheet from Professor Lavelle's chem14a website, there is something listed as "1 atm = 101.325 kPa" Could someone please explain what this means? We haven't gotten to this section of chemistry (pressure) yet, so you do not have to worry about it for the u...
- Sun Oct 25, 2020 4:43 pm
- Forum: Properties of Electrons
- Topic: intensity vs energy
- Replies: 29
- Views: 3115
Re: intensity vs energy
As many have already discussed, this statement is decidedly false. When we go to the quantum level, the level of one photon, the energy will not increase. This is because increasing intensity increases the number of photons of light, rather than the individual energy of each photon. More photons doe...
- Sun Oct 25, 2020 4:40 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Graphs on Midterm
- Replies: 4
- Views: 98
Re: Graphs on Midterm
I haven't heard anything about graphs specifically on the midterm. From what I have gathered, the midterm will be split between conceptual problems and more mathematical ones. A graph could pop up based on this information, but we will likely have see it before or be able to interpret it.
- Sun Oct 25, 2020 4:37 pm
- Forum: Photoelectric Effect
- Topic: Mass of atoms
- Replies: 18
- Views: 532
Re: Mass of atoms
As some such as Halle have already stated, the equations and constants sheets will have the mass of protons, electrons, and neutrons provided. We'll be using kg as the unit of choice as other constants/equations will be dependent on this unit.
- Wed Oct 21, 2020 4:17 pm
- Forum: Properties of Electrons
- Topic: Properties of Electrons and Matter as a Whole
- Replies: 5
- Views: 240
Properties of Electrons and Matter as a Whole
Am I correct in thinking that electrons possess both wave-like and particle-like properties? Additionally, basically all matter possesses particle-like properties, but can matter's wavelike properties only be detected at very small scales?
- Sun Oct 18, 2020 3:01 pm
- Forum: DeBroglie Equation
- Topic: Names of equations
- Replies: 8
- Views: 282
Re: Names of equations
I think it would be helpful to familiarize yourself with the equations, so that you can recognize when to use them on the exam. If you do not know its name, be able to name its purpose and the components that make up the formula.
- Sun Oct 18, 2020 2:59 pm
- Forum: Photoelectric Effect
- Topic: Light Intensity
- Replies: 23
- Views: 403
Re: Light Intensity
Yes, you are correct! If they had changed the wavelength or frequency, they would have changed the type of light being shown. As many have already stated, increasing the intensity led to an increase in total photons rather than individual photon energy. This is a problem on the quantum level where a...
- Sun Oct 18, 2020 2:56 pm
- Forum: Properties of Light
- Topic: Equation masterlist
- Replies: 6
- Views: 335
Re: Equation masterlist
Hi! You can access them on the chemistry 14a website under "constants and equations" (right below the tab "Everything you want to know about Sig Fig"). If you do not see it, I have the link to it: https://lavelle.chem.ucla.edu/wp-content/supporting-files/Chem14A/constants_equati...
- Sun Oct 18, 2020 2:54 pm
- Forum: *Black Body Radiation
- Topic: Black Body Radiation
- Replies: 6
- Views: 457
Re: Black Body Radiation
I am not sure if this is the same concept in action. From what I recall Dr. Lavelle discussing, black body radiation is a theoretical discussion as nothing we know of absorbs all wavelengths of light. Though, color and light absorption would be an interesting discussion. Polar bears are known for th...
- Sun Oct 18, 2020 2:46 pm
- Forum: Photoelectric Effect
- Topic: Practice Quiz Question
- Replies: 3
- Views: 72
Re: Practice Quiz Question
I believe a keV is a kiloelectron volt, a thousand electron volts, and a unit of energy. What is an electron volt? An electron volt is the unit equal to the amount of kinetic energy gained by an electron accelerating through a electric potential difference of one volt from rest. One eV is equal to 1...
- Fri Oct 09, 2020 7:57 pm
- Forum: Properties of Light
- Topic: Amplitude and Velocity Relationship
- Replies: 3
- Views: 93
Re: Amplitude and Velocity Relationship
My understanding is that amplitude does not affect wave velocity. However, amplitude has more to do with the energy or intensity of the light? I'm not 100% sure though, anyone can feel free to correct me. I think you're correct. Amplitude is independent of frequency in simple harmonic motion which ...
- Fri Oct 09, 2020 7:51 pm
- Forum: Balancing Chemical Reactions
- Topic: Whole Number Stoichiometric Coefficients
- Replies: 12
- Views: 1435
Re: Whole Number Stoichiometric Coefficients
As a few have already stated, the convention is to make the stoichiometric coefficients whole numbers. I think it generally makes the balanced equation easier to grasp and look neater overall. Having fractions unnecessarily complicates things, but it can be a bit of work to get there depending on th...
- Fri Oct 09, 2020 7:43 pm
- Forum: Properties of Light
- Topic: Why do salts with different cations burn different colors?
- Replies: 2
- Views: 750
Re: Why do salts with different cations burn different colors?
I am not well versed in salt-burning-coloration, however I do believe it is important to note the difference between a physical and chemical change. The element's color (a physical property) does not necessarily have an impact on what color it will burn (a chemical property). For example, you know N...