Search found 104 matches
- Fri Mar 12, 2021 1:54 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Are catalysts consumed?
- Replies: 37
- Views: 1986
Re: Are catalysts consumed?
I don't think we need to know too much about catalysts for the exam, but they are not consumed. I wouldn't stress too much about this topic. However, if you are curious, I attached an article that goes into a more in depth description of catalysts. http://ch302.cm.utexas.edu/kinetics/catalysts/catal...
- Fri Mar 12, 2021 1:52 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Week 10 Posts
- Replies: 5
- Views: 797
Re: Week 10 Posts
I assume that this would be the case however I am not completely sure. I would say to just get all your posts in today before midnight just to be safe.
- Fri Mar 12, 2021 1:16 pm
- Forum: General Rate Laws
- Topic: Sapling #5
- Replies: 8
- Views: 477
Re: Sapling #5
And for the second part of this question, you would do the same thing essentially, just switching the values you use. For example, you would do (3^1)(0.5^2)(initial rate given).
- Fri Mar 12, 2021 1:00 pm
- Forum: Environment, Ozone, CFCs
- Topic: catalysis vs intermediate
- Replies: 25
- Views: 2103
Re: catalysis vs intermediate
Everyone above described a catalyst vs intermediate very well. I just thought I would give an example, so you can see their definitions in action... A+B-->AB AB+C-->AC+B Based on these equations, we can see that AB is an intermediate, for it is first produced, then consumed. Species B is a catalyst ...
- Thu Mar 11, 2021 9:39 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Equations and Derivations/Integrations
- Replies: 4
- Views: 347
Re: Equations and Derivations/Integrations
I would review the sapling problems from week 1 to week 10, and see the equations you used to solve those problems. I would do this while looking at the equations sheet. For example, read a question and refer to the equation sheet just to practice and get familiarized with the location of where ever...
- Sun Mar 07, 2021 7:42 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Saying Thank You to Dr. Lavelle
- Replies: 490
- Views: 621596
Re: Saying Thank You to Dr. Lavelle
Dr. Lavelle, I wanted to write and say thank you for teaching me about chemistry for the past two quarters. Your videos, or lectures, always started off with music, that made my mornings that much sweeter (#djlavelle). I hope one day we can meet in person on campus, and exchange some chemistry puns!...
- Sun Mar 07, 2021 7:37 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3889712
Re: Post All Chemistry Jokes Here
How do you laugh in a "chemist's" language?
HeHe
HeHe
- Sun Mar 07, 2021 7:34 pm
- Forum: Student Social/Study Group
- Topic: Culinary Chemistry
- Replies: 239
- Views: 40993
Re: Culinary Chemistry
Its crazy to think that any cooking we do involves chemistry. Like even cutting an avocado in half sets off a chemical reaction that changes the green flesh of the avocado to a brownish color. CRAZY
- Sun Mar 07, 2021 7:29 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: Concept of Order (n)
- Replies: 7
- Views: 480
Re: Concept of Order (n)
I feel that everyone above did a great job explaining, but just thought a summary of equations could be useful to you all! I attached it below :)
- Sun Mar 07, 2021 7:26 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Gibbs Energy
- Replies: 20
- Views: 1174
Re: Gibbs Energy
As students above have mentioned, Gibbs free energy combines enthalpy and entropy into a single value. If delta G is negative, the reaction is spontaneous. If delta G is positive, the reaction is non-spontaneous. When delta G is equal to 0, the system is at equilibrium.
- Sun Feb 28, 2021 3:16 pm
- Forum: Student Social/Study Group
- Topic: Post Midterm 2 De-stressing
- Replies: 92
- Views: 8578
Re: Post Midterm 2 De-stressing
I distressed by eating at my favorite sandwich shop. Then taking a nap when I got home, and then watching wandavision when I woke up :)
- Sun Feb 28, 2021 2:56 pm
- Forum: Balancing Redox Reactions
- Topic: Sapling 7/8 Question 3
- Replies: 2
- Views: 261
Re: Sapling 7/8 Question 3
To solve this question, you just need to balance the two half reactions individually before putting them together! Cr -> CrO 4 2- Balance O using H2O: Cr + 4H 2 O -> CrO 4 2- Balance H using H+: Cr + 4H 2 O -> CrO 4 2- + 8H + Balance charge using e - : Cr + 4H 2 O -> CrO 4 2- + 8H + + 6e - Cu 2+ ->...
- Sun Feb 28, 2021 2:00 pm
- Forum: Balancing Redox Reactions
- Topic: Sapling #5
- Replies: 9
- Views: 605
Re: Sapling #5
Lorraine Jiang 2C wrote:Hi! I had the same issue but I fixed it by putting H2O as the last item on one side of the equation.
Hope it helps!
Omg I am going to try this and hope it works. I swear I have the right answer, just going to rearrange it now!
- Sun Feb 28, 2021 1:45 pm
- Forum: Balancing Redox Reactions
- Topic: Understanding Oxidation Agents
- Replies: 13
- Views: 702
Re: Understanding Oxidation Agents
Would we be able to determine how strong of an oxidizing agent an element could be by looking at the periodic table?
- Sun Feb 28, 2021 1:33 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Sapling HW Week 7/8 #18
- Replies: 2
- Views: 245
Re: Sapling HW Week 7/8 #18
Hi Adam! I started by writing the unbalanced equation with the reactants on the left side and products on the right. The question states that "rust is caused by iron reacting with oxygen gas in the presence of water to create an oxide layer." So the reactants would be Fe + O2 + H2O. Then ...
- Sun Feb 21, 2021 6:28 pm
- Forum: Student Social/Study Group
- Topic: Winter GEs?
- Replies: 33
- Views: 2947
Re: Winter GEs?
I really enjoyed my communications class this quarter, COMM 10. It was super interesting and pretty easy. I also enjoyed my literature class, ComLit2CW with professor Komar. It satisfies your diversity requirement and one other requirement (I think your analysis one?), but it is a lot of heavy readi...
- Sun Feb 21, 2021 6:24 pm
- Forum: Student Social/Study Group
- Topic: Fave food
- Replies: 266
- Views: 47256
Re: Fave food
Popcorn and cinnamon toast are my favorite comfort foods. They always are delicious for any occasion.
- Sun Feb 21, 2021 6:23 pm
- Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
- Topic: state functions
- Replies: 6
- Views: 475
Re: state functions
Heat and Work are not state functions because they are dependent on the path used to go from the initial to final state. State functions by definition only depend on the state of the system, not the path used to get to that state. I hope this explanation was somewhat helpful!
- Sun Feb 21, 2021 6:17 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: R Constant
- Replies: 91
- Views: 7760
Re: R Constant
As students have mentioned above, the R constant you use depends on the context of the problem!
- Sun Feb 21, 2021 6:15 pm
- Forum: Student Social/Study Group
- Topic: Post Midterm 2 De-stressing
- Replies: 92
- Views: 8578
Re: Post Midterm 2 De-stressing
Yes we love Wanda Vision! I just plan on getting outside, maybe the beach because the sound of the waves crashing on the shore is so therapeutic.
- Sun Feb 14, 2021 4:01 pm
- Forum: Student Social/Study Group
- Topic: Final Jitters
- Replies: 457
- Views: 418017
Re: Final Jitters
I am super worried for finals this quarter because chemistry is a lot more complex this quarter (thermochemistry is the death of me!). However, power naps and watching comedic relief shows on Netflix or Hulu help relieve some anxiety.
- Sun Feb 14, 2021 3:59 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Sapling week 5/6 question 18
- Replies: 8
- Views: 1992
Re: Sapling week 5/6 question 18
I followed the correct steps (and the same ones I followed for part b), but keep getting a very large number for k. Any idea why this might be? I had the same problem. have you checked all the signs of your values? I realized I didn't carry a negative sign from one of the table values which gave me...
- Sun Feb 14, 2021 3:57 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Is it necessary to memorize Cp,m or Cv,m values? [ENDORSED]
- Replies: 26
- Views: 1478
Re: Is it necessary to memorize Cp,m or Cv,m values? [ENDORSED]
No you do not! I believe that they are on the equation sheet.
- Sun Feb 14, 2021 3:56 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: temperature
- Replies: 32
- Views: 1452
Re: temperature
Depending on the context of the problem you might have to convert a few things, including temperature. Just make sure you pay attention to the wording and context of a problem because it can be the difference between a right answer and a wrong answer!
- Sun Feb 14, 2021 3:54 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Closed vs Isolated System
- Replies: 30
- Views: 1484
Re: Closed vs Isolated System
A closed system can exchange energy with its surroundings (not matter like in an open system), whereas an isolated system cannot exchange matter with either its surroundings nor matter.
Example of Closed System: putting ice on injury
Example of Isolated System: sealed vacuum flask
Example of Closed System: putting ice on injury
Example of Isolated System: sealed vacuum flask
- Sun Feb 07, 2021 6:48 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3889712
Re: Post All Chemistry Jokes Here
What's the difference between and optimist, a pessimist, and a chemist?
An optimist sees the glass half full, a pessimist sees the glass half empty, and the chemist sees the glass full with half liquid and half gas.
An optimist sees the glass half full, a pessimist sees the glass half empty, and the chemist sees the glass full with half liquid and half gas.
- Sun Feb 07, 2021 6:41 pm
- Forum: Calculating Work of Expansion
- Topic: Sapling #18
- Replies: 8
- Views: 593
Re: Sapling #18
The way to solve for ΔU also depends on the molar specific heat of the gas. For q, you use the constant-pressure molar specific heat, which you are given as 4R. However, the equation for ΔU is ΔU = nCvΔT The ΔU equation requires the constant-volume molar specific heat. So how are constant-pressure ...
- Sun Feb 07, 2021 6:31 pm
- Forum: Calculating Work of Expansion
- Topic: Sapling #14 for Wk 3 and 4
- Replies: 12
- Views: 627
Re: Sapling #14 for Wk 3 and 4
The first path is a reversible expansion so you would use w = -nRTln(V2/V1). However you first need to find moles so you would use the ideal gas law to find it (n = PV/RT). Then once you solved for moles you input it in -nRTln(V2/V1). For Path B because it is at a constant pressure, irreversible re...
- Sun Feb 07, 2021 6:16 pm
- Forum: Calculating Work of Expansion
- Topic: Sapling 15
- Replies: 6
- Views: 628
Re: Sapling 15
Although great answers have been said above, I will reiterate what they stated. First use stoichiometry to calculate the number of moles of N2 produced. Second use the PV=nRT equation. (Your value for R in this scenario will be 0.0821, the value for your temperature must be in Kelvin...) Third, with...
- Sun Feb 07, 2021 6:09 pm
- Forum: Calculating Work of Expansion
- Topic: Sapling #14
- Replies: 4
- Views: 283
Re: Sapling #14
As what other students mentioned above, the many different R values are used depending on the situation of the given problem. I was confused too with all the different R values!
- Sun Jan 31, 2021 12:33 pm
- Forum: Student Social/Study Group
- Topic: Sapling Homework
- Replies: 7
- Views: 436
Re: Sapling Homework
As said above, ask questions on chemistry community! Or even in the Chem GroupMe app. Adila helps answering a lot of people's questions. Don't Gove up! You got this :)
- Sun Jan 31, 2021 12:31 pm
- Forum: Student Social/Study Group
- Topic: Worried About MT 1 Grades
- Replies: 39
- Views: 2153
Re: Worried About MT 1 Grades
Last quarter I struggled with the Lavelle's tests even after studying the best I knew how to. However, going to all the UA sessions helped a lot. As did doing the textbook questions. I too am worried about grades, but remember that we still have two more exams in this class that we can improve upon!...
- Sun Jan 31, 2021 12:29 pm
- Forum: Student Social/Study Group
- Topic: How to relax
- Replies: 168
- Views: 34768
Re: How to relax
To relax I usually listen to music!
- Sun Jan 31, 2021 12:27 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3889712
Re: Post All Chemistry Jokes Here
Gold is the best element. Why you ask?
Because it is AU-some.
Because it is AU-some.
- Sun Jan 31, 2021 12:18 pm
- Forum: Phase Changes & Related Calculations
- Topic: Sapling Week 3/4 Q10
- Replies: 3
- Views: 282
Sapling Week 3/4 Q10
An ice cube with a mass of 50.0 g at 0.0 ∘C is added to a glass containing 387 g of water at 45.0 ∘C. Determine the final temperature of the system at equilibrium. The specific heat capacity of water, Cs is 4.184 J/g⋅∘C and the standard enthalpy of fusion, ΔH∘fus of water is 6.01×10^3 J/mol. Assume ...
- Sat Jan 23, 2021 10:43 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Studying for Midterm #1
- Replies: 63
- Views: 3135
Re: Studying for Midterm #1
Definitely put in the hours to study. I would read the sections of the textbook he assigned in the outlines, as well as the textbook problems. In addition UA session are super helpful!
- Sat Jan 23, 2021 10:42 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Homework number six
- Replies: 4
- Views: 272
Re: Homework number six
I would definitely review materials for chem 14a if you had Lavelle, specifically strong acids and bases. This made identifying acidic, basic, and neutral so much easier! I believe a list of the strong acids and bases is on Sapling as well.
- Sat Jan 23, 2021 10:39 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: ICE Tables
- Replies: 36
- Views: 2002
Re: ICE Tables
The values of x, or rather the quantity of it, does correspond to the stoichiometric coefficients of the balanced chemical equation.
- Sat Jan 23, 2021 10:37 pm
- Forum: Student Social/Study Group
- Topic: How to relax
- Replies: 168
- Views: 34768
Re: How to relax
I took a meditating fiat lux class in the fall and it definitely helps me relax. It is nice to just sit and breathe for a minute, and not have to think about anything in particular. If you are interested in meditation I would definitely recommend taking Professor Shorter's Meditation fiat lux if he ...
- Sat Jan 23, 2021 10:35 pm
- Forum: Student Social/Study Group
- Topic: Favorite TV shows
- Replies: 277
- Views: 49916
Re: Favorite TV shows
Criminal Minds is always good (if you're into criminology and profiling). If you're looking for something that is more upbeat and funny, I feel like New Girl and Impractical Jokers never fail to make me laugh. As for childhood shows, Big Time Rush was one of my favorites. I also really enjoyed Julie...
- Sat Jan 16, 2021 6:09 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3889712
Re: Post All Chemistry Jokes Here
What's the dullest element?
Bohrium!
Bohrium!
- Sat Jan 16, 2021 5:58 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: When x is negligible in Equilibrium constant
- Replies: 34
- Views: 1678
Re: When x is negligible in Equilibrium constant
Smaller than 10^-3 he said!
- Sat Jan 16, 2021 5:52 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: pH of Weak Acids
- Replies: 11
- Views: 496
Re: pH of Weak Acids
Yeah I was having similar thoughts. I feel that this would be a good question to bring up to Professor Lavelle during his office hours for a clear and distant answer. (If there is a distinct answer.)
- Sat Jan 16, 2021 5:46 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Using Kw
- Replies: 5
- Views: 220
Re: Using Kw
Depending on the context of the problem, Kw can be used in a multitude of ways. However, primarily it is used to find the H3O+ and the OH- concentrations. ( [H3O+][OH-]=Kw=1.0 x 10^-14 ) If you are given the pOH of the pH and need to find the other, you could used this equation: pH + pOH = 14. If yo...
- Sat Jan 16, 2021 5:40 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Le Chatelier's Principle Basics
- Replies: 4
- Views: 319
Re: Le Chatelier's Principle Basics
In Dr. Lavelle's lectures for week 1, he covers that chemical reactions adjust to minimize the effect of changes... Le Chatelier's Principle. He also says that Le Chatelier's Priciple applies to changing physical parameters (Pressure and Temperature). I would definitely review that last section of t...
- Sat Jan 09, 2021 5:59 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3889712
Re: Post All Chemistry Jokes Here
what do you do with a sick chemist?
if you can't helium, and you can't curium, you might as well barium.
if you can't helium, and you can't curium, you might as well barium.
- Sat Jan 09, 2021 5:51 pm
- Forum: Ideal Gases
- Topic: value of R
- Replies: 24
- Views: 1135
Re: value of R
To know which value of R to use, make sure you read the problem that you are doing carefully. It should give you context clues as to whether you are dealing with atms, bars, etc. Then you would use the R value for the specific unit.
- Sat Jan 09, 2021 5:49 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Change in Pressure
- Replies: 9
- Views: 246
Re: Change in Pressure
By increasing the pressure (only applies to gases), you would be decreasing the overall volume. This would result in an increase of concentration.
- Sat Jan 09, 2021 5:43 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: K vs. Q
- Replies: 53
- Views: 2472
Re: K vs. Q
So if we are given Kc and then are told to calculate Q with the given concentrations of the products and reactants, Q would tell us if the reaction is at equilibrium or if the reaction leans toward the products/reactants?
- Thu Jan 07, 2021 6:07 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: HW problem
- Replies: 4
- Views: 239
Re: HW problem
I would look at the responses written under the tab of Sapling Problem #5 (Of this section) because students have given very detailed and helpful answers there!
- Thu Jan 07, 2021 6:05 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Sapling #5
- Replies: 4
- Views: 196
Re: Sapling #5
When looking at this problem yesterday I had no idea how to do it. After my discussion session today where we did a similar problem, I now understand how to go about this problem. First you need to figure out which equations listed have the reactants and products you are looking for (know that you c...
- Wed Dec 16, 2020 10:53 pm
- Forum: *Titrations & Titration Calculations
- Topic: Titration Curves
- Replies: 2
- Views: 685
Re: Titration Curves
I believe that Professor Lavelle will go into more detail about titrations in Chem 14B. But based on the last lecture in 14A, the graph he depicted was a titration curve. It showed us the volume of the titrant on the x-axis and the pH on the y-axis. This graph also tells us the stoichiometric or equ...
- Wed Dec 16, 2020 10:48 pm
- Forum: Student Social/Study Group
- Topic: Existing 14B Groupme
- Replies: 4
- Views: 413
Re: Existing 14B Groupme
The chemistry 14A GroupMe group chat converted into a Chem 14B group chat. Let me know if you need the link to join!
- Wed Dec 16, 2020 10:45 pm
- Forum: Ideal Gases
- Topic: Reading the textbook
- Replies: 262
- Views: 155963
Re: Reading the textbook
Are there a lot of topics in the book that are not covered during lecture that show up on tests? I feel that on the midterms, doing the practice problems from the textbook helped a lot. So for next quarter I recommend keeping up with textbook material as it is being taught in lectures. I feel that ...
- Wed Dec 16, 2020 10:43 pm
- Forum: Lewis Acids & Bases
- Topic: Lewis vs Bronsted
- Replies: 20
- Views: 1257
Re: Lewis vs Bronsted
As stated above, Lewis acids/bases have to deal with electrons whereas Bronsted acids/bases deal with H+ ions.
- Wed Dec 16, 2020 10:38 pm
- Forum: Student Social/Study Group
- Topic: grade worries
- Replies: 119
- Views: 23922
Re: grade worries
Hey you guys just remember that it is many of your first quarter at UCLA with everything being virtual. Try not to stress to much!
- Sun Dec 06, 2020 8:36 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3889712
Re: Post All Chemistry Jokes Here
What do you call and acid with an attitude?
A - meano - acid :)
A - meano - acid :)
- Sun Dec 06, 2020 8:33 pm
- Forum: Naming
- Topic: Number after Metal
- Replies: 9
- Views: 545
Re: Number after Metal
The Roman numeral after the metal, written in parenthesis, represents the oxidation state of that metal.
- Sun Dec 06, 2020 8:31 pm
- Forum: Bronsted Acids & Bases
- Topic: Acids as proton donors
- Replies: 4
- Views: 303
Re: Acids as proton donors
As someone had already said above, the two definitions describe an acid, but the Bronsted definition deals with the protons and the Lewis definition deals with the electrons. I find that reading the textbook clarified these two definitions.
- Sun Dec 06, 2020 8:29 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final Grade
- Replies: 9
- Views: 782
Re: Final Grade
I am not quite sure when we will receive our final grade, but I assume it will be shortly after we take our final exam.
- Sun Dec 06, 2020 8:28 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Sapling Week 9
- Replies: 6
- Views: 496
Re: Sapling Week 9
The answer is just octahedral. Octahedral is a COMMON shape for the coordination number 6. I think when I looked at the explanation for this problem it said that pentagonal pyramidal was not common.
- Sun Nov 29, 2020 11:11 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Ligands
- Replies: 4
- Views: 329
Re: Ligands
Yes! Ligands must have one or more lone pairs. Just a bit of extra information that Lavelle covered in his last lecture (11/26/20) that we need to know is: Ligands bind at: 1 site (donate 1 e- pair) --> Monodentate 2 sites (donate 2e- pair) --> Bidentate 3 sites (donate 3e- pair) --> Tridentate 6 si...
- Sun Nov 29, 2020 11:04 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Coordination Number and Regions of density
- Replies: 8
- Views: 808
Re: Coordination Number and Regions of density
In Lavelle's last lecture (11/26/20), he said that the number of bonds was equal to the coordination number.
- Sun Nov 29, 2020 11:01 am
- Forum: Hybridization
- Topic: sp and sp2
- Replies: 7
- Views: 437
Re: sp and sp2
I am pretty sure we don't need to know what these orbitals look like, rather we just have to know what the hybridization of a molecule will be based off the number of electron densities present on the central atom. However, I would ask this question in office hours with Lavelle to double check!
- Sun Nov 29, 2020 10:58 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR Chart
- Replies: 18
- Views: 1071
Re: VSEPR Chart
Hi I found this really good website to study the VSEPR chart. http://intro.chem.okstate.edu/1314F00/Lecture/Chapter10/VSEPR.html Yes! This is the website the Justin recommended during his workshop and it is really helpful for visualizing the molecular shapes. He just reminded us to double check the...
- Sun Nov 29, 2020 10:48 am
- Forum: Industrial Examples
- Topic: Bond rotations
- Replies: 10
- Views: 1884
Re: Bond rotations
What exactly makes single bonds capable of rotation and double bonds unable to do so? I definitely would rewatch Lavelle's Week 7 Friday Lecture (11/20/20). He draws out sigma and pi bonds and does a demonstration with a pencil that explains why double bonds are incapable of rotating. I have attach...
- Sun Nov 22, 2020 5:31 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Sapling question
- Replies: 4
- Views: 191
Re: Sapling question
When I went to Justin's UA session, he said that we are not required to know the exact angle. However, we are supposed to give an approximate angle, such as less than or greater than 90 degrees.
- Sun Nov 22, 2020 5:29 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Sapling Week 7-8 #2
- Replies: 3
- Views: 301
Re: Sapling Week 7-8 #2
The answer would be square planar! Check out the website I linked below for more help with identifying molecular geometry!
http://intro.chem.okstate.edu/1314F00/L ... VSEPR.html
http://intro.chem.okstate.edu/1314F00/L ... VSEPR.html
- Sun Nov 22, 2020 5:26 pm
- Forum: Student Social/Study Group
- Topic: Exercising Our Minds and Bodies
- Replies: 120
- Views: 27089
Re: Exercising Our Minds and Bodies
I usually have intermittent dance parties in my room throughout the day. I also watch youtube dance videos and try and copy the choreography, but I am not the best dancer. I try and run but finding the motivation to run can be hard.
- Sun Nov 22, 2020 5:22 pm
- Forum: Student Social/Study Group
- Topic: Big Sad: Midterm 2
- Replies: 86
- Views: 8035
Re: Big Sad: Midterm 2
Remember, if you struggled with these topics, try and go to as many step-up and UA sessions as possible. They are honestly such a HUGE help since they go over more complex examples and relate it back to the concepts Lavelle discusses in lectures. We also still have a final to take! Try not to stress...
- Sun Nov 22, 2020 5:19 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Thanksgiving week lectures
- Replies: 5
- Views: 395
Re: Thanksgiving week lectures
As everyone said above, pretty sure we will still have lectures and discussion sections as scheduled up to Wednesday, but since we have Thursday and Friday off, I would say there are no discussion sections / lectures scheduled. However, I would wait and watch Monday's lecture and keep and ear open f...
- Sun Nov 22, 2020 5:17 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: different shapes given in notes
- Replies: 4
- Views: 361
Re: different shapes given in notes
When I went to Justin's UA session, he said that we should know more shapes just to be safe, but also to help us prepare of organic chemistry. He shared a link with us during his Saturday session which allows you to see a visual of each of the shapes in the VSEPR Model. I have attached the link belo...
- Sun Nov 15, 2020 2:05 pm
- Forum: Trends in The Periodic Table
- Topic: Trends on the Period Table
- Replies: 8
- Views: 623
Re: Trends on the Period Table
I would definitely recommend reviewing the lectures from Lavelle since he covers all the trends we should know for the upcoming midterm.
- Sun Nov 15, 2020 2:04 pm
- Forum: Trends in The Periodic Table
- Topic: Atomic radius
- Replies: 4
- Views: 285
Re: Atomic radius
If you want more clarification for atomic radii, I would look at the period table that Lavelle had put in his lectures. I have attached the link to a similar one below... I hope this helps! https://www.google.com/url?sa=i&url=http%3A%2F%2Fcrystalmaker.com%2Fsupport%2Ftutorials%2Fatomic-radii%2Fi...
- Sun Nov 15, 2020 1:58 pm
- Forum: Student Social/Study Group
- Topic: Midterm 2
- Replies: 22
- Views: 968
Re: Midterm 2
For the midterm I am reviewing my lecture notes, doing practice worksheets from the UA sessions, and working on textbook problems. I personally like making flash cards for each of the concepts on the outlines, to know what I have to study more.
- Sun Nov 15, 2020 1:54 pm
- Forum: Ionic & Covalent Bonds
- Topic: Metals and Nonmetals in p block
- Replies: 3
- Views: 202
Re: Metals and Nonmetals in p block
Before the exam, you can only have a periodic table that is on Lavelle’s website. However, once the exam starts you can draw whatever you want on the period table, including trends and the line that distinguishes metals from non metals in the p-block.
- Sun Nov 15, 2020 1:47 pm
- Forum: Coordinate Covalent Bonds
- Topic: Lewis Acid Identification
- Replies: 3
- Views: 245
Re: Lewis Acid Identification
I had a clarification question about Lewis Acids and Bases. I know that Lewis Acids accept an electron pair and a Lewis Base donates and electron pair. I also know that acids and bases combine to form a coordinate covalent bond. I was wondering if there is a trick to identifying Lewis Acids and Base...
- Sun Nov 08, 2020 5:10 pm
- Forum: Student Social/Study Group
- Topic: grade worries
- Replies: 119
- Views: 23922
Re: grade worries
I feel like worrying about grades is common grounds for all students, especially us UCLA overachiever students. However, just do your best because that's all you can do. But if you continue to worry, it's all good. Only 4 more weeks to go!
- Sun Nov 08, 2020 5:06 pm
- Forum: Administrative Questions and Class Announcements
- Topic: MIDTERM 2 Textbook Sections
- Replies: 6
- Views: 303
Re: MIDTERM 2 Textbook Sections
I am not sure up to exactly where in the textbook (for Midterm 2), however, completing the problems that are covering the same topics as lectures would be the safest bet. As well as following the outlines.
- Sun Nov 08, 2020 4:57 pm
- Forum: Electronegativity
- Topic: periodic table
- Replies: 16
- Views: 880
Re: periodic table
I found this image that has a summarization of periodic table trends. I have attached the image below. Hope you find it helpful!
- Sun Nov 08, 2020 4:50 pm
- Forum: Student Social/Study Group
- Topic: Midterm 2 Study Group
- Replies: 25
- Views: 1224
Re: Midterm 2 Study Group
This is amazing! I will definitely join this group me to get as much extra help and studying in as possible.
- Sun Nov 08, 2020 4:48 pm
- Forum: Student Social/Study Group
- Topic: Final Jitters
- Replies: 457
- Views: 418017
Re: Final Jitters
This year I have been taking a meditation course that has been helping me with my anxiety. Just taking a few minutes out of your day to focus on your breathing has been a big help for me personally. However, if you have more final jitters regarding content, making a study guide and a study group wou...
- Sun Nov 01, 2020 8:28 pm
- Forum: Properties of Light
- Topic: Sapling #10
- Replies: 11
- Views: 606
Re: Sapling #10
Did you convert from meters to nanometers correctly? Or did you type an error into your calculator by accident? Those are the only issues I can seem to think of.
- Sun Nov 01, 2020 8:23 pm
- Forum: Student Social/Study Group
- Topic: Sappling week 2 problem #23
- Replies: 1
- Views: 197
Re: Sappling week 2 problem #23
To solve this problem you must first use the equation E=(hc)/lamda. Once you find the energy using this equation, convert to electron volts. (This constant value can be found on the Constants and Equations Worksheet provided by Lavelle.) Then make sure you take the difference of this value that you ...
- Sun Nov 01, 2020 8:15 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: sapling 13
- Replies: 7
- Views: 382
Re: sapling 13
In Lavelle's lectures, he talked about what each of the variables represent. I believe it was his week 3 Friday Lecture. I have attached a picture that should help with this problem.
- Sun Nov 01, 2020 8:09 pm
- Forum: Properties of Electrons
- Topic: Sapling Question (Bohr and Broglie Models of Electrons)
- Replies: 4
- Views: 937
Re: Sapling Question (Bohr and Broglie Models of Electrons)
When answering this problem, remember that the wave must interfere constructively with itself. In other terms, it must be complete wavelengths. (Whole number of wavelengths).
- Mon Oct 26, 2020 7:40 pm
- Forum: Photoelectric Effect
- Topic: Sapling Week 2 HW_problem #25
- Replies: 3
- Views: 144
Re: Sapling Week 2 HW_problem #25
When solving this problem, the 2.4 micro meter is the wavelength. So knowing this, you can still use the E = hv equation, but you also must use the c=wavelength(frequency) equation to substitute your known variables to find the energy of the photon. You will eventually get E=h(c/wavelength). When yo...
- Sun Oct 25, 2020 8:15 pm
- Forum: *Black Body Radiation
- Topic: Midterm
- Replies: 14
- Views: 821
Re: Midterm
How do we know what will be on the midterm please help i am freaking out. Is there a place where we can figure this out or do we just go to office hours. The syllabus has a bunch of practice problems that Lavelle recommends doing. Those questions are fair game for the midterm, so I would definitely...
- Sun Oct 25, 2020 8:11 pm
- Forum: Properties of Light
- Topic: Midterm
- Replies: 42
- Views: 1791
Re: Midterm
It's still a bit unclear about the amount of material we are able to use for the midterm; I thought I heard he was going to provide a printout sheet for the formulas, but I have not gotten an email about this. We are able to use a sheet of constants and equations that he provides to us and a period...
- Sun Oct 25, 2020 8:03 pm
- Forum: Empirical & Molecular Formulas
- Topic: Periodic Table and Calculations
- Replies: 21
- Views: 1761
Re: Periodic Table and Calculations
Are we able to use graphing calculators for the midterm? I heard some TAs are accepting them but I'm not sure if this is true for every section. I am pretty sure if you have a graphing calculator (the TI-84), it is acceptable. My TA said that because the majority of students have that calculator fr...
- Sun Oct 25, 2020 2:32 pm
- Forum: Naming
- Topic: Formulas based on names
- Replies: 8
- Views: 1431
Re: Formulas based on names
Professor Lavelle does go over a lot of high school chemistry, but he didn't go over nomenclature. He also said all necessary tools to solve a problem will be given to us on an exam. However, when doing examples in my discussion session with my TA, she says that a lot of molecular compound names sho...
- Sun Oct 25, 2020 2:26 pm
- Forum: SI Units, Unit Conversions
- Topic: units to know for midterm
- Replies: 11
- Views: 845
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?
Could someone please explain what this means?
- Thu Oct 22, 2020 4:49 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: What is a nodal plane?
- Replies: 4
- Views: 324
What is a nodal plane?
In the lecture on Wednesday (10/21), Professor Lavelle was talking about orbitals. He mentioned that orbitals p, d, and f have a nodal plane. Could someone explain what a nodal plane is please?
- Sun Oct 18, 2020 4:37 pm
- Forum: Properties of Electrons
- Topic: Wave properties of elecrons
- Replies: 5
- Views: 445
Re: Wave properties of elecrons
Hi! When two waves are in the same path, energy is always conserved and the end results will depend on the waves. For constructive waves, two waves will combine energies together usually because they are in phase (their crests line up), ultimately increasing the amplitude of the wave. The opposite ...
- Sun Oct 18, 2020 4:27 pm
- Forum: Photoelectric Effect
- Topic: Short/high wavelength
- Replies: 7
- Views: 330
Re: Short/high wavelength
What is the actual reason for the fact that shorter wavelength/higher frequency light can eject electrons but longer wavelength/lower frequency light cannot? Each photon must have enough energy to eject an electron, and low frequency light has no photons with sufficient energy to f=do this. Increas...
- Sun Oct 18, 2020 4:13 pm
- Forum: Properties of Light
- Topic: Balmer Series vs Lyman Series
- Replies: 3
- Views: 245
Re: Balmer Series vs Lyman Series
Just remember that Balmer series is in the visible region whereas the Lyman series is in the UV region. I also attached a diagram that was included in Lecture 6 that I drew out in my notes. I hope you find it helpful!
- Sun Oct 18, 2020 4:03 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Exams
- Replies: 12
- Views: 667
Re: Exams
Also regarding exams, I wanted to confirm that constants will be given to us. This is correct right? Because I remember him saying that we didn't need to memorize constants in one of our lectures.
- Sun Oct 18, 2020 4:00 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Downloading Chemistry Textbook
- Replies: 1
- Views: 158
Downloading Chemistry Textbook
When I went to Lavelle's office hours, he said that there was an app that we needed to install on our computer order to download the textbook onto our computers. Does anyone know what app this might have been?
- Sun Oct 11, 2020 5:12 pm
- Forum: Significant Figures
- Topic: All students read this sig fig post [ENDORSED]
- Replies: 170
- Views: 36392
Re: All students read this sig fig post [ENDORSED]
In my discussion class, my TA said that 0.500g is only 1 significant figure. I am pretty sure it was 3 significant figures, but I just wanted to double check here. I'm certain 0.500 has 3 significant figures because trailing zeroes are taken into account because there's a decimal point. Leading zer...
- Sun Oct 11, 2020 5:11 pm
- Forum: Significant Figures
- Topic: All students read this sig fig post [ENDORSED]
- Replies: 170
- Views: 36392
Re: All students read this sig fig post [ENDORSED]
In my discussion class, my TA said that 0.500g is only 1 significant figure. I am pretty sure it was 3 significant figures, but I just wanted to double check here. The Sig figs sheet on Lavelle's website states that trailing zeros with a decimal point are counted as significant. Take a look at that...