Search found 101 matches
- Fri Mar 12, 2021 7:54 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: cell diagram from lecture
- Replies: 3
- Views: 269
Re: cell diagram from lecture
I'm sure you're right. I haven't watched the review lecture yet, but the image you provided asks "What is wrong with this cell diagram?" so that should be a mistake that we are expected to recognize, along with the mistake pointed out by Sameer above my post.
- Fri Mar 12, 2021 7:48 pm
- Forum: First Order Reactions
- Topic: Half Life Unit
- Replies: 38
- Views: 1834
Re: Half Life Unit
You should look at the units you use in your question/problem. Just make sure that if they initially give you values in hours and the final answer requires the units to be in seconds, that you do the hours to seconds conversion or vice versa if they ask the other way around.
- Fri Mar 12, 2021 7:47 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Slow Step
- Replies: 14
- Views: 1483
Re: Slow Step
The slow step doesn't occur as fast as the other elementary steps. Thus, the rate of the reaction as a whole essentially depends on the rate of this slow step. The step before the slow step will be considered in equilibrium because there will be a build-up of products and some of the products will g...
- Fri Mar 12, 2021 7:43 pm
- Forum: Student Social/Study Group
- Topic: chem community points
- Replies: 23
- Views: 1350
Re: chem community points
You need to have made 50 posts by Sunday March 14th while in Chem 14B. Some students will have more because they either posted more than 50 posts this quarter or they had Chem 14A with Lavelle and made posts during that quarter.
- Fri Mar 12, 2021 7:42 pm
- Forum: Student Social/Study Group
- Topic: Spring Quarter
- Replies: 60
- Views: 4378
Re: Spring Quarter
Because I am a biochem major, I had to move from the 14 series onto the 20 series. So instead of taking 14BL, I have to take 20L.
- Sun Mar 07, 2021 5:22 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cathode in Diagrams
- Replies: 6
- Views: 442
Re: Cathode in Diagrams
Cathodes I have seen have always been on the right, and the anode on the left. Everyone else's posts here also suggest the same, so it should be safe to assume this for 14B.
- Sun Mar 07, 2021 5:18 pm
- Forum: Student Social/Study Group
- Topic: Chem Community Points
- Replies: 35
- Views: 2006
Re: Chem Community Points
50 points is the cap for chem community posts, so you can't get extra credit from doing more posts. You get up to 5 points per week and each point is rewarded for every individual post or reply you make, as long as it is in the correct category.
- Sun Mar 07, 2021 5:15 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidizing Reactant
- Replies: 9
- Views: 703
Re: Oxidizing Reactant
I look at an "agent" as being something that causes something. So a reducing agent causes reduction, also meaning that the reducing agent was oxidized. An oxidizing agent causes oxidation, which then means that the oxidizing agent was reduced. To determine the oxidizing agent, look for the...
- Sun Mar 07, 2021 5:12 pm
- Forum: Administrative Questions and Class Announcements
- Topic: [CHEM 14B KARAOKE]
- Replies: 68
- Views: 7759
Re: [CHEM 14B KARAOKE]
This event was really cool, especially that it was planned out by fellow classmates and supported by our professor and TAs. Hopefully, this becomes an annual tradition for Lavelle's 14 series courses, I'm sure future students would find as much fun as we did.
- Sun Mar 07, 2021 5:09 pm
- Forum: Student Social/Study Group
- Topic: How do you deal with burnout?
- Replies: 144
- Views: 24047
Re: How do you deal with burnout?
I think the best way to deal with burnout is to go outside. Being locked up at home doing work or spending hours at your computer isn't good for your mental. I would suggest going out for a drive, some exercise (even if you just take a walk), or go get some food or a treat. Listening to music helps ...
- Sun Feb 28, 2021 7:43 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: E vs E naught
- Replies: 36
- Views: 1960
Re: E vs E naught
E naught is the value of E at standard conditions: 1 atm, 25 degrees celsius, and 1 M.
- Sun Feb 28, 2021 7:41 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Sapling Question #19
- Replies: 6
- Views: 466
Re: Sapling Question #19
Your equation for E naught should be -(-74.0 x 10^3 J) / (3 mol)(96485 C/mol). This comes from the formula E naught = -(delta G naught) / nF.
- Sun Feb 28, 2021 7:38 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: E naught = 0
- Replies: 13
- Views: 2066
Re: E naught = 0
At standard conditions, the concentrations are equal and thus E naught would be equal to 0.
- Sun Feb 28, 2021 7:35 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Sapling #16 Wk7/8
- Replies: 8
- Views: 1832
Re: Sapling #16 Wk7/8
According to my solution on Sapling, it states that, "Because lnQ and n both double, the effect cancels out in the Nernst equation, meaning E remains constant."
- Sun Feb 28, 2021 7:32 pm
- Forum: General Science Questions
- Topic: Chem Jokes
- Replies: 28
- Views: 1990
Re: Chem Jokes
Why do chemists like working with ammonia?
Because it's pretty basic stuff.
Because it's pretty basic stuff.
- Sun Feb 21, 2021 11:16 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Delta G and G naught
- Replies: 46
- Views: 4871
Re: Delta G and G naught
Delta G is the change in Gibbs free energy at any conditions, while delta G naught is the change in Gibbs free energy change at standard conditions (e.g. 298K and 1 atm).
- Sun Feb 21, 2021 11:13 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Spontaneity of a System
- Replies: 38
- Views: 3065
Re: Spontaneity of a System
In the most simplest terms, when delta G is negative then the reaction is spontaneous and favorable in the forward direction. If delta G is positive, then the reaction is nonspontaneous and favorable in the reverse direction. You can use equations such as " delta G = delta H - T(delta S) "...
- Sun Feb 21, 2021 11:10 am
- Forum: Student Social/Study Group
- Topic: We made it through Midterm 2!
- Replies: 71
- Views: 5470
Re: We made it through Midterm 2!
I still need one more midterm this Monday and I'm finally done with grinding out my study sessions. Good luck to those who are reading this and have another exam(s) to go!
- Sun Feb 21, 2021 11:08 am
- Forum: Student Social/Study Group
- Topic: Has anyone taken Chem 20L before?
- Replies: 3
- Views: 418
Has anyone taken Chem 20L before?
As a biochem major, I have to make the switch over to the 20 series after taking 14B and I was wondering if anyone had taken 20L before or is taking it this quarter. How is the workload, or do you have any tips for me as I take the course this spring?
- Sun Feb 21, 2021 11:04 am
- Forum: Student Social/Study Group
- Topic: Points needed to pass?
- Replies: 76
- Views: 11721
Re: Points needed to pass?
I think you need 90% for an A- and so forth like what we were used to in high school, but instead of the minimum for a C- being something like 70%, it's 50% for this class. Lavelle never really explained grades, except for that a 50% gives a C-.
- Sun Feb 14, 2021 7:03 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Likeliness to form products/reactants
- Replies: 27
- Views: 1091
Re: Likeliness to form products/reactants
When delta G is + then the reverse reaction will be favored (favor more reactants). When delta G is - then the forward reaction will be favored (favor more products).
- Sun Feb 14, 2021 6:59 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Units
- Replies: 20
- Views: 834
Re: Units
I've seen questions have the final units required to be in both kilojoules or in joules. The conversion between the two is really easy to remember, so it shouldn't matter which one you choose to use as long as the question doesn't specify. Just remember to pay attention to your units so that you alw...
- Sun Feb 14, 2021 6:55 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: difference in ΔG and ΔG⁰
- Replies: 15
- Views: 774
Re: difference in ΔG and ΔG⁰
The "naught sign" a.k.a. "⁰" just refers to the unit being in standard conditions (which are 298K and 1 atm). If it doesn't give the naught sign, then the unit may still be in standard conditions but you have to figure out if it is, or it is in other conditions.
- Sun Feb 14, 2021 6:52 pm
- Forum: Student Social/Study Group
- Topic: Silly Mistakes?
- Replies: 72
- Views: 7690
Re: Silly Mistakes?
Extremely positive chem community post! Thanks for sharing this vibe with everyone in the class.
- Sun Feb 14, 2021 6:50 pm
- Forum: Student Social/Study Group
- Topic: Classes for next quarter?
- Replies: 165
- Views: 22711
Re: Classes for next quarter?
I'm going to be enrolling in my 3rd quarter for my Cluster 70 course, LS7B, Math 32A, and most likely Chem 14C!
- Sun Feb 07, 2021 6:55 pm
- Forum: Student Social/Study Group
- Topic: Identifying Dr. Lavelle's Music
- Replies: 15
- Views: 1006
Re: Identifying Dr. Lavelle's Music
I think we should try to get Lavelle to drop his Chem 14 Series Playlist. Would make for some decent background music while I fry my brain studying.
- Sun Feb 07, 2021 6:52 pm
- Forum: Student Social/Study Group
- Topic: Chemistry Community Posts
- Replies: 12
- Views: 782
Re: Chemistry Community Posts
I just always count the number of posts I make within the week that is going to be graded. I don't really look at the total number of posts because I sometimes post more than 5 times a week by accident.
- Sun Feb 07, 2021 6:49 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Bond breaking and forming
- Replies: 11
- Views: 422
Re: Bond breaking and forming
I usually draw out the Lewis structures like Lavelle did during the lecture. I think we are already supposed to know how to draw them because that was 14A content. Once I draw the structures of the reactants and products, I am able to tell which bonds were broken and/or formed.
- Sun Feb 07, 2021 6:47 pm
- Forum: Phase Changes & Related Calculations
- Topic: Define Phase Change
- Replies: 78
- Views: 6168
Re: Define Phase Change
A phase change is a change in the state of matter where the different states are solid, liquid and gas. So a phase change is a change from one of the states I mentioned to another state.
- Sun Feb 07, 2021 6:40 pm
- Forum: Phase Changes & Related Calculations
- Topic: Boiling water
- Replies: 25
- Views: 3240
Re: Boiling water
When water is boiled, the hydrogen bonds between the water molecules are broken. These bonds are the strongest IMFs, so that's why it takes a large amount of heat to break them.
- Sun Jan 31, 2021 2:11 pm
- Forum: Phase Changes & Related Calculations
- Topic: Vapor vs gas
- Replies: 121
- Views: 16918
Re: Vapor vs gas
Yes, they are the same, they both refer to something in the gaseous state.
- Sun Jan 31, 2021 2:09 pm
- Forum: Phase Changes & Related Calculations
- Topic: midterm respondus
- Replies: 19
- Views: 958
Re: midterm respondus
After you install it, you can run it to see how it works. It's pretty easy, and just removes access to your browser and other applications like Siri if you're on Mac.
- Sun Jan 31, 2021 2:06 pm
- Forum: Phase Changes & Related Calculations
- Topic: endothermic/exothermic
- Replies: 43
- Views: 5078
Re: endothermic/exothermic
As you go from a state of lower energy to higher energy (like solid --> liquid --> gas) it requires energy and is endothermic. As you go from a state of higher to lower energy (like gas --> liquid ---> solid) it releases energy and is exothermic.
- Sun Jan 31, 2021 2:04 pm
- Forum: Student Social/Study Group
- Topic: Favorite Music
- Replies: 113
- Views: 17178
Re: Favorite Music
I don't really listen to music while studying because noise distracts me, but I always make sure to listen to music throughout the day outside of school. I listen to R&B (ex: Brent Faiyaz, The Weeknd) or usually rap (ex: Young Thug, Travis Scott).
- Sun Jan 31, 2021 2:00 pm
- Forum: Student Social/Study Group
- Topic: Guyssssss...(midterm)
- Replies: 22
- Views: 1231
Re: Guyssssss...(midterm)
Regardless of how we feel, we can't go back and change our test. We have to continue the grind for the next midterm. You guys got this, good luck!
- Sun Jan 24, 2021 1:33 pm
- Forum: Ideal Gases
- Topic: reversing reactions
- Replies: 83
- Views: 6646
Re: reversing reactions
When you have a reaction A+B-->C and have its K value and then reverse the reaction to C-->A+B, the K value of this reverse reaction will be the inverse of the first K value.
- Sun Jan 24, 2021 1:30 pm
- Forum: Ideal Gases
- Topic: Inverse Kc [ENDORSED]
- Replies: 41
- Views: 2711
Re: Inverse Kc [ENDORSED]
You use the inverse of the K value when you want to find the K value of the reverse reaction. So if you are given K for A+B-->C and you want the K for C-->A+B then you take the inverse of the first K.
- Sun Jan 24, 2021 1:21 pm
- Forum: Student Social/Study Group
- Topic: Midterms During Lecture
- Replies: 44
- Views: 2646
Re: Midterms During Lecture
Whether we will take the midterm in a large lecture zoom call or a discussion zoom call, I think it will work like our final in 14A where our TA invites all of their students into one zoom call and are split into two groups where 2 proctors look over one of the groups respectively.
- Sun Jan 24, 2021 1:18 pm
- Forum: Student Social/Study Group
- Topic: Advice for study
- Replies: 31
- Views: 1750
Re: Advice for study
I highly recommend attending the various review sessions (UA, review, etc) and also working on the textbook problems as those were the most similar to the questions we had on the exams in 14A.
- Sun Jan 24, 2021 1:16 pm
- Forum: Student Social/Study Group
- Topic: Midterm
- Replies: 21
- Views: 1117
Re: Midterm
The midterm shouldn't be too long. I remember having a good amount of time to revise my answers for both midterm 1 and 2. However, I can't say the same for the final. You shouldn't expect more than 20 questions, I would guess around the 10-20 question range, but more towards the lower end of that if...
- Sun Jan 17, 2021 2:36 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Kc and Kp
- Replies: 11
- Views: 509
Re: Kc and Kp
Kc is used when you are dealing with a question about concentrations or molarity. Kp is used when you are dealing with partial pressures.
- Sun Jan 17, 2021 2:33 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Sapling Number 4
- Replies: 5
- Views: 2248
Re: Sapling Number 4
Using your numbers, I got the equation 383x^2 +x -0.0320 = 0. Then using the quadratic formula, I get two values (a negative and positive value) where the positive value equals 0.00792789. Maybe you made an error when you wrote out your quadratic equation? I would double-check your math to see if yo...
- Sun Jan 17, 2021 2:25 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Sapling HW1 Question 9
- Replies: 6
- Views: 362
Re: Sapling HW1 Question 9
The concentration of NO will decrease by 2x and the concentrations for both N2 and O2 will increase by x.
- Sun Jan 17, 2021 2:21 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Ice Box Method
- Replies: 14
- Views: 586
Re: Ice Box Method
When choosing the sign of the x value in an ICE box, you have to look at whether the concentration of the products and reactants are decreasing or increasing. You can usually tell which situation it is when you get information on the question such as "participant X has an initial concentration ...
- Sun Jan 17, 2021 2:17 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Adding together two equilibrium equations
- Replies: 5
- Views: 417
Re: Adding together two equilibrium equations
Yes. When you increase the moles in an equilibrium equation, the moles of every reactant/product increase as well. So if you double the moles of one participant, you also have to double the moles of every other participant.
- Sun Jan 10, 2021 12:09 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: K vs Q
- Replies: 7
- Views: 314
Re: K vs Q
Q is the ratio of products to reactants during any time in a reaction, so I would say to use Q when you are unsure. But I would think that a question in this course would give you the K value so you wouldn't have to be unsure. If you're in a lab environment and don't have a known K value, then you c...
- Sun Jan 10, 2021 12:02 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: H2O
- Replies: 44
- Views: 2296
Re: H2O
Solids and liquids are omitted, so only H2O as a gas should be included.
- Sun Jan 10, 2021 11:56 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Sign of x in ICE Box
- Replies: 8
- Views: 472
Re: Sign of x in ICE Box
The reactant(s), or molecule(s) being consumed, will have a negative x value. While the product(s), or molecule(s) being formed will have a positive x value. You just have to look at what molecule(s) are being consumed or produced to decide if they have an addition or subtraction.
- Sun Jan 10, 2021 11:53 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: K vs. Q
- Replies: 53
- Views: 2735
Re: K vs. Q
Yes, that's correct, Q is just the ratio at any time during the reaction and K (equilibrium constant) is the ratio when the reaction is at equilibrium.
- Sun Jan 10, 2021 11:51 am
- Forum: Ideal Gases
- Topic: Non-Ideal gases?
- Replies: 26
- Views: 1166
Re: Non-Ideal gases?
I don't think we'll be covering this in 14B.
- Thu Dec 17, 2020 5:59 am
- Forum: General Science Questions
- Topic: final timing
- Replies: 25
- Views: 1727
Re: final timing
Compared to both midterms, where I had plenty of time to go over my answers twice, the final really had me struggling to stay within the "3 minutes per question" time frame. I ran out of time and had to guess the answers I couldn't spend time on. I should have probably gone through all the...
- Thu Dec 17, 2020 5:56 am
- Forum: General Science Questions
- Topic: Passing Grade
- Replies: 34
- Views: 2506
Re: Passing Grade
The 50% refers to the amount of points that we can acquire in the class. The class is out of 500 pts so 250 pts would be needed to pass.
- Thu Dec 17, 2020 5:54 am
- Forum: General Science Questions
- Topic: Grades
- Replies: 30
- Views: 2495
Re: Grades
You can find your grade on CCLE, but I would check Saturday when the grade for our final is posted.
- Thu Dec 17, 2020 5:52 am
- Forum: Student Social/Study Group
- Topic: Curve?
- Replies: 50
- Views: 7073
Re: Curve?
I've heard that it is based on class average once final scores are complete and listed.
- Thu Dec 17, 2020 5:50 am
- Forum: Student Social/Study Group
- Topic: Course Evals
- Replies: 18
- Views: 1090
Re: Course Evals
I had my math course evaluation required for 1% of my final grade, but it doesn't seem like this course requires it.
- Sun Dec 06, 2020 8:14 pm
- Forum: Student Social/Study Group
- Topic: final study
- Replies: 42
- Views: 2433
Re: final study
I will definitely go over the previous outlines to see which textbook problems to go over because Lavelle mentioned that the Final's questions will be based off of them. I also plan to attend review sessions from the TAs and UAs, and especially the ones that Lavelle is hosting.
- Sun Dec 06, 2020 8:12 pm
- Forum: Hybridization
- Topic: pi bonds
- Replies: 6
- Views: 398
Re: pi bonds
There would be 2 pi bonds in CH3CN between the C atom and N atom because there would be a triple bond. All bonds contain one sigma bond while double and triple bonds have additional pi bonds.
- Sun Dec 06, 2020 5:24 pm
- Forum: Hybridization
- Topic: Pi Bonds Cannot Rotate
- Replies: 29
- Views: 4402
Re: Pi Bonds Cannot Rotate
This picture does a pretty good job at showing how a pi bond would break.
- Sun Dec 06, 2020 5:16 pm
- Forum: Hybridization
- Topic: Good video about hybridization
- Replies: 7
- Views: 540
Re: Good video about hybridization
Thank you, I'll add this to my review plan!
- Sun Dec 06, 2020 5:14 pm
- Forum: Administrative Questions and Class Announcements
- Topic: CCLE fixed?
- Replies: 19
- Views: 1099
Re: CCLE fixed?
CCLE is up again but there are still some issues with the site as in functionality.
- Sun Nov 29, 2020 6:37 pm
- Forum: Student Social/Study Group
- Topic: Midterm Exam Questions
- Replies: 16
- Views: 953
Re: Midterm Exam Questions
Try talking to your TA to set up an appointment to go over your own exam if you can't have a general discussion of it because of time in your discussion class.
- Sun Nov 29, 2020 6:34 pm
- Forum: Student Social/Study Group
- Topic: Happy Thanksgiving!
- Replies: 39
- Views: 2508
Re: Happy Thanksgiving!
Happy late thanksgiving, my family makes tamales this time of year for the holidays.
- Sun Nov 29, 2020 6:30 pm
- Forum: Student Social/Study Group
- Topic: Chem 14B with 20L
- Replies: 6
- Views: 499
Re: Chem 14B with 20L
Is there no prerequisite for 20L that is a 20 series class? Or in other words, we don't have to previously taken a specific 20 series class to enroll in 20L? Nope! 14A, 20A, and 20AH can each fulfill the prerequisite, and 14B, 20B, and 20BH can fulfill the corequisite. Ah okay, thank you for the cl...
- Sun Nov 29, 2020 6:26 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Lecture #24 Ligands and Complexes
- Replies: 5
- Views: 302
Re: Lecture #24 Ligands and Complexes
Yeah, he meant tetrahedral instead of octahedral.
- Sun Nov 29, 2020 6:24 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: coordination number
- Replies: 13
- Views: 647
Re: coordination number
Yes, it is equal to the total number of bonds. A single bond gives one, double bond gives two, and a triple bond gives 3.
- Sun Nov 29, 2020 6:22 pm
- Forum: Student Social/Study Group
- Topic: Chemistry Among Us
- Replies: 43
- Views: 2958
Re: Chemistry Among Us
I think sticking close with purple is a safer bet.
- Sun Nov 22, 2020 1:29 am
- Forum: Bond Lengths & Energies
- Topic: IMF vs. Intramolecular Forces
- Replies: 7
- Views: 581
Re: IMF vs. Intramolecular Forces
I believe that question would be asking about intramolecular forces because you are comparing the bonds within two separate molecules (meaning atom with atom in each molecule).
- Sun Nov 22, 2020 1:25 am
- Forum: Student Social/Study Group
- Topic: Grading Scale for Chem14A
- Replies: 29
- Views: 1942
Re: Grading Scale for Chem14A
I hope he does give back points, but maybe that would make us feel a little too comfortable.
- Sun Nov 22, 2020 1:23 am
- Forum: Student Social/Study Group
- Topic: Chem 14B with 20L
- Replies: 6
- Views: 499
Re: Chem 14B with 20L
Is there no prerequisite for 20L that is a 20 series class? Or in other words, we don't have to previously taken a specific 20 series class to enroll in 20L?
- Sun Nov 22, 2020 1:20 am
- Forum: Student Social/Study Group
- Topic: Periodic Table on Midterm
- Replies: 5
- Views: 379
Re: Periodic Table on Midterm
You're only ever allowed a non-marked version of the periodic table on Lavelle's website. Just make sure you know the trends by memory for all of his exams.
- Sun Nov 22, 2020 1:19 am
- Forum: Student Social/Study Group
- Topic: Winter 2021 Classes
- Replies: 20
- Views: 1230
Re: Winter 2021 Classes
As long as you have 12 units you're good!
- Sat Nov 14, 2020 8:11 pm
- Forum: Bond Lengths & Energies
- Topic: Size
- Replies: 13
- Views: 849
Re: Size
005162520 wrote:Does bond length also affect how strong the bond is?
Yes, the larger a bond length the further two atoms are and the weaker than bond is.
- Sat Nov 14, 2020 8:07 pm
- Forum: Bond Lengths & Energies
- Topic: Sapling HW Bond Length
- Replies: 7
- Views: 438
Re: Sapling HW Bond Length
It is actually S that has a larger atomic radius than O. You might have confused the trend for atomic radii on the period table.
- Sat Nov 14, 2020 8:04 pm
- Forum: Dipole Moments
- Topic: Sapling #19
- Replies: 12
- Views: 652
Re: Sapling #19
Yes it is a mistake, it should be SO2.
- Sat Nov 14, 2020 8:00 pm
- Forum: Student Social/Study Group
- Topic: VSEPR Chart
- Replies: 5
- Views: 513
Re: VSEPR Chart
We are expected to know/memorize the chart because it's not going to be given.
- Sat Nov 14, 2020 7:58 pm
- Forum: Student Social/Study Group
- Topic: Chemistry Among Us
- Replies: 43
- Views: 2958
Re: Chemistry Among Us
Call out green, why would they extend their arm?
- Sun Nov 08, 2020 2:17 pm
- Forum: Student Social/Study Group
- Topic: Studying From Home
- Replies: 91
- Views: 10151
Re: Studying From Home
I would recommend taking consistent rest breaks to relax your eyes off of your computer screen. We are required to now spend hours looking at a computer screen which fatigues our sight and mind. Definitely use your breaks to do something where you don't look at any screens. I usually take a nap sinc...
- Sun Nov 08, 2020 2:12 pm
- Forum: Electronegativity
- Topic: Atom size
- Replies: 22
- Views: 3405
Re: Atom size
As you go up a group and also across a period to the right on the periodic table, the electronegativity increases. Now, if you go down a group and towards the left on the periodic table, the size of the atom increases.
- Sun Nov 08, 2020 2:06 pm
- Forum: Lewis Structures
- Topic: Negative Sign
- Replies: 12
- Views: 943
Re: Negative Sign
If you are talking about the charge of the molecule represented by the Lewis structure, then the charge (along with its number) will go outside of the structure's brackets.
- Sun Nov 08, 2020 2:04 pm
- Forum: Student Social/Study Group
- Topic: Midterm 1
- Replies: 4
- Views: 321
Re: Midterm 1
I do not think that we will be reviewing the midterm as we need to move on and prepare for midterm 2. If you have some questions, the drop in sessions should be a good way to get some understanding.
- Sun Nov 08, 2020 2:02 pm
- Forum: Student Social/Study Group
- Topic: Chemistry Among Us
- Replies: 43
- Views: 2958
Re: Chemistry Among Us
I would go help shut off the reactor.
- Sun Nov 01, 2020 4:16 pm
- Forum: Trends in The Periodic Table
- Topic: Metalloids/Non-Metals on the Periodic Table
- Replies: 6
- Views: 1826
Re: Metalloids/Non-Metals on the Periodic Table
I think mnemonics are great for remembering, but I just have memorized them by remembering a color coordinated periodic table. Maybe try looking at one a couple times a day or using one when you work on problems that require you to refer to the periodic table, so that you get that image in your head...
- Sun Nov 01, 2020 4:07 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Fall 2020 Midterm 1 Instructions
- Replies: 20
- Views: 2070
Re: Fall 2020 Midterm 1 Instructions
I've heard that grading has been delayed for whatever reason, although I'm not sure if that is really the case. So I would assume that we might have to wait a week or two before we receive our scores.
- Sun Nov 01, 2020 4:02 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: wavelength
- Replies: 13
- Views: 685
Re: wavelength
Wavelength cannot be negative, but you might calculate energy to be negative. This would just mean that energy was released in that chemical process described in the question.
- Sun Nov 01, 2020 3:58 pm
- Forum: *Black Body Radiation
- Topic: Info for Midterm
- Replies: 13
- Views: 1206
Re: Info for Midterm
Black body radiation isn't something that we go into depth for this course. So it will not be in any midterms or the final.
- Sun Nov 01, 2020 3:54 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Chem Community Posts
- Replies: 10
- Views: 335
Re: Chem Community Posts
Also, make sure to create posts that are related to the topic you are posting under. Any posts should be valid as long as you are contributing in some way.
- Sun Oct 25, 2020 5:01 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Emitting a Photon
- Replies: 9
- Views: 369
Re: Emitting a Photon
A photon is emitted as an electron goes down one energy level. Once it is at the ground state, a photon cannot be emitted as there is no energy level below the ground state.
- Sun Oct 25, 2020 4:52 pm
- Forum: Einstein Equation
- Topic: m vs nm
- Replies: 66
- Views: 4347
Re: m vs nm
If I remember correctly, Lavelle mentioned that either unit is fine for a general answer. However, if a question asks for something concerning a wavelength, it is best to convert the units to nanometers (nm) as wavelength is given in that unit.
- Sun Oct 25, 2020 4:48 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: h/4pi
- Replies: 7
- Views: 310
Re: h/4pi
We use h/4pi because writing out the actual value of this constant wouldn't be convenient. It is much easier to write this out as h/4pi and then plug in the values into the calculator when it comes time to do so in the question.
- Sun Oct 25, 2020 4:41 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Heisenbergs equation example from lecture
- Replies: 4
- Views: 158
Re: Heisenbergs equation example from lecture
That number is the mass of an electron, it's just a given and it is listed on the "Constants and Equations" handout Lavelle provided for us to use during our midterms and final in case you don't memorize it along the incoming weeks.
- Sun Oct 25, 2020 4:33 pm
- Forum: Properties of Electrons
- Topic: intensity vs energy
- Replies: 29
- Views: 3516
Re: intensity vs energy
An increase in intensity does not relate to an increase in energy of a photon. Intensity only relates to the number of photons, not the energy each photon has. It is the frequency of a photon that determines its energy.
- Sun Oct 18, 2020 12:45 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Accessing the E-textbook [ENDORSED]
- Replies: 125
- Views: 36813
Re: Accessing the E-textbook [ENDORSED]
If you are still waiting to receive an access code in the mail after purchasing the e-textbook with Sapling through the UCLA store, try calling or e-mailing to see if you can receive your code digitally rather than having to wait.
- Sun Oct 18, 2020 12:42 pm
- Forum: Student Social/Study Group
- Topic: groupme?
- Replies: 2
- Views: 360
Re: groupme?
I am not sure if there is a GroupMe for that specific discussion, but you can ask around about it in the main GroupMe or you can create one with your discussion peers next time you meet them in your weekly discussion zoom call.
- Sun Oct 18, 2020 12:40 pm
- Forum: General Science Questions
- Topic: Rusty on High School Chem [ENDORSED]
- Replies: 347
- Views: 486419
Re: Rusty on High School Chem [ENDORSED]
You shouldn't worry too much. A lot of us are also rusty on our chemistry as some of us haven't taken it since our sophomore year in high school. If you ever are in need of any help, you may use Chemistry Community, the step-up sessions, or any of the discussion zoom calls that Lavelle hosts (there ...
- Sun Oct 18, 2020 12:31 pm
- Forum: General Science Questions
- Topic: E-Book
- Replies: 3
- Views: 300
Re: E-Book
On the home page of this course on Sapling, the e-textbook should be located on the very right side of the page under the Clock. It will then open up a new page (where I think you might need to sign in if it is your first time accessing the e-textbook) and you should be good to go.
- Sun Oct 18, 2020 12:22 pm
- Forum: Balancing Chemical Reactions
- Topic: States of Molecules
- Replies: 9
- Views: 439
Re: States of Molecules
I believe that if you're balancing an equation that is already given to you, the states of the molecules should already be given to you too. If they are not, I do not believe that it is necessary to go and find out what state of matter they are in. For knowing which state of matter each molecule is...
- Sun Oct 11, 2020 11:50 am
- Forum: Balancing Chemical Reactions
- Topic: States of Matter in Chemical Equations
- Replies: 13
- Views: 347
Re: States of Matter in Chemical Equations
If the states of matter are given to you in an unbalanced chemical reaction, definitely include them when you balance. However, if the states of matter are not given to you initially, I don't believe it is necessary, at this level, to search the states of matter to include in the balanced chemical r...
- Sun Oct 11, 2020 11:40 am
- Forum: Balancing Chemical Reactions
- Topic: States of Molecules
- Replies: 9
- Views: 439
Re: States of Molecules
I believe that if you're balancing an equation that is already given to you, the states of the molecules should already be given to you too. If they are not, I do not believe that it is necessary to go and find out what state of matter they are in. For knowing which state of matter each molecule is ...
- Sun Oct 11, 2020 11:32 am
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Stochiometric Coefficients
- Replies: 6
- Views: 522
Re: Stochiometric Coefficients
No, stoichiometric coefficients do not have units. They just indicated a number that is related to the number of moles of the compound it represents.
- Sun Oct 11, 2020 11:29 am
- Forum: Balancing Chemical Reactions
- Topic: Balancing Chemical Reactions Order
- Replies: 49
- Views: 7103
Re: Balancing Chemical Reactions Order
I don't believe there is a correct way to balance chemical reactions, but I find it effective to first balance the element that has the most bonds, which is typically carbon. I hope somewhat helps you out.