Search found 62 matches
- Sun Mar 17, 2019 4:15 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Effect of increased concentration on equilibrium
- Replies: 9
- Views: 1488
Re: Effect of increased concentration on equilibrium
The reactions will form products to restore equilibrium
- Sun Mar 17, 2019 4:12 pm
- Forum: Balancing Redox Reactions
- Topic: Triprotic
- Replies: 7
- Views: 3759
Re: Triprotic
Yes, a triprotic acid has 3 protons, or 3 hydrogens
- Sat Mar 16, 2019 12:15 am
- Forum: *Enzyme Kinetics
- Topic: sig figs on the final
- Replies: 2
- Views: 572
Re: sig figs on the final
I know that sig figs were definitely included in the points for some of the questions on the midterm, so i would assume it will be the same on the final although I'm not sure how much they will be worth.
- Sun Mar 10, 2019 10:01 pm
- Forum: Student Social/Study Group
- Topic: Final
- Replies: 24
- Views: 2207
Re: Final
Here's a link to the final review session information: https://lavelle.chem.ucla.edu/wp-conten ... ns_14B.pdf
- Sun Mar 10, 2019 9:55 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final Questions
- Replies: 10
- Views: 1212
Re: Final Questions
I would expect around 8 questions, but with multiple parts similar to the format of the midterm.
- Sun Mar 10, 2019 9:55 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Final Exam
- Replies: 23
- Views: 1803
Re: Final Exam
yes, the final covers everything we've covered in class so chemical equilibrium will definitely show up.
- Wed Feb 27, 2019 7:07 pm
- Forum: Ideal Gases
- Topic: Q and K
- Replies: 13
- Views: 1320
Re: Q and K
Q can be calculated at any point in the reaction, whereas K is only calculated at equilibrium
- Wed Feb 27, 2019 10:28 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Question for Test 2
- Replies: 4
- Views: 455
Re: Question for Test 2
yes you should probably know it since it was covered in lecture last week.
- Wed Feb 27, 2019 10:26 am
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: n
- Replies: 8
- Views: 847
Re: n
n in this equation is the moles of electrons transferred in your balanced redox reaction
- Sun Feb 24, 2019 9:31 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: n value
- Replies: 11
- Views: 947
Re: n value
the textbook says that n in this equation is the number of miles of electrons transferred in the reaction.
- Sun Feb 24, 2019 9:28 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagrams
- Replies: 2
- Views: 327
Re: Cell Diagrams
According to the textbook, one vertical line represents interface between two phases, two vertical lines represents a salt bridge, and a comma is used to separate species in the same phase.
- Sun Feb 24, 2019 9:25 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagram Lines
- Replies: 3
- Views: 335
Re: Cell Diagram Lines
One vertical line represents interface between phases while two vertical lines represents a salt bridge.
- Sun Feb 17, 2019 11:12 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: Midterm Grades
- Replies: 35
- Views: 2772
Re: Midterm Grades
Most likely we will get the midterms back this coming week in our discussion sections
- Sun Feb 17, 2019 11:09 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: HW for W7
- Replies: 7
- Views: 687
Re: HW for W7
I think Gibbs free energy is fine as long as it's stuff from after the midterm
- Sun Feb 17, 2019 11:07 pm
- Forum: Student Social/Study Group
- Topic: Test
- Replies: 17
- Views: 1584
Re: Test
Dr. Lavelle's website says "Test 2 covers all topics on Gibbs free energy and electrochemistry up to the Nernst equation"
- Sun Feb 10, 2019 9:21 pm
- Forum: Calculating Work of Expansion
- Topic: Derivatives and Integrals
- Replies: 5
- Views: 661
Re: Derivatives and Integrals
I wouldn't expect integrals or derivatives to be on the midterm, I think they were just used to show how certain equations were derived. It can't hurt to review and know them, though.
- Sun Feb 10, 2019 9:18 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Study Guides
- Replies: 15
- Views: 1275
Re: Study Guides
Lyndon made one that you can find if you search "hotdog" on chemistry community.
- Sun Feb 10, 2019 9:16 pm
- Forum: General Science Questions
- Topic: Midterm Formulas
- Replies: 1
- Views: 462
Re: Midterm Formulas
I'm not 100% sure but I think the constants and formulas page will be the same on the midterm as on the first test. Here's the link to it: https://lavelle.chem.ucla.edu/wp-conten ... ations.pdf
- Mon Feb 04, 2019 10:05 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Midterm [ENDORSED]
- Replies: 49
- Views: 4871
Re: Midterm [ENDORSED]
I would definitely do all the homework problems, as well as going over any old tests. The review sessions are helpful, especially going to the ones that are on topics you're having trouble with
- Mon Feb 04, 2019 10:03 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Isolated System (Water bottle)
- Replies: 6
- Views: 1856
Re: Isolated System (Water bottle)
Because it's insulated, there is no energy exchange between the inside and outside of the waterbottle. An isolated system is characterized by there being no matter or energy transfer between the system and the surroundings
- Mon Feb 04, 2019 10:02 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Cup of Tea
- Replies: 17
- Views: 2543
Re: Cup of Tea
It's open because it can exchange both matter and energy with its surroundings. For example, you can add or take away tea and it can also be cooled or heated.
- Sun Jan 27, 2019 3:36 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Calculating Q
- Replies: 11
- Views: 3805
Re: Calculating Q
You can calculate Q at any point in the reaction and it will tell you if the reaction is at equilibrium and, if not, which direction the reaction will proceed.
- Sun Jan 27, 2019 3:34 pm
- Forum: Phase Changes & Related Calculations
- Topic: Modules
- Replies: 17
- Views: 1324
Re: Modules
They're not mandatory, but they are very helpful especially when studying for tests or the midterm/final.
- Sun Jan 27, 2019 3:31 pm
- Forum: Phase Changes & Related Calculations
- Topic: Week 4 Homework
- Replies: 12
- Views: 1258
Re: Week 4 Homework
Yes, I think as long as it's from Thermochemistry (outline 3) you're fine.
- Wed Jan 16, 2019 10:51 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Test topics for next week
- Replies: 3
- Views: 347
Re: Test topics for next week
Dr. Lavelle's website says "Test 1 covers Equilibrium and Acid & Base Equilibria"
- Wed Jan 16, 2019 10:50 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Le Chatelier's Principle
- Replies: 4
- Views: 443
Re: Le Chatelier's Principle
Removing product as it is formed results in more product yield because the reaction will keep trying to reach equilibrium as product is removed, so the reactants will continue being turned into product.
- Wed Jan 16, 2019 10:47 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Number of questions on test one [ENDORSED]
- Replies: 39
- Views: 21672
Re: Number of questions on test one [ENDORSED]
the test takes place during your discussion section starting Tuesday of next week. Also, I had Caram last quarter and we had weekly quizzes each worth 5 points total but he would write the number of points each question was worth next to the questions so we knew how much weight each question carrie...
- Sun Jan 13, 2019 7:39 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Calculating Q
- Replies: 7
- Views: 484
Re: Calculating Q
Q is calculated the same way as K, so you will always have products over reactants
- Sun Jan 13, 2019 7:38 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Example in Class
- Replies: 7
- Views: 444
Re: Example in Class
When you take away some of the product, the reaction is no longer at equilibrium so it will continue reacting in the forward direction, yielding more NH3
- Sun Jan 13, 2019 7:37 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Kp Units
- Replies: 6
- Views: 552
Re: Kp Units
Kp doesn't have units because they cancel out, so I don't think it matters as long as you use the same units throughout your calculations
- Fri Dec 07, 2018 11:08 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Molecular shape
- Replies: 3
- Views: 404
Re: Molecular shape
I think the coordination number for this is actually 6 because the central platinum atom is bonded to 5 chlorines and 1 ammonia. This would explain why it's octahedral because octahedral is something with 6 regions of electron density.
- Fri Dec 07, 2018 10:59 am
- Forum: Amphoteric Compounds
- Topic: Amphiprotic vs. amphoteric
- Replies: 3
- Views: 498
Re: Amphiprotic vs. amphoteric
Here's a resource I found helpful: https://www.chemguide.co.uk/physical/ac ... ories.html
Basically amphoteric compounds are not necessarily amphiprotic because some Lewis acids and bases can act as both acids and bases but don't necessarily donate/accept hydrogen ions
Basically amphoteric compounds are not necessarily amphiprotic because some Lewis acids and bases can act as both acids and bases but don't necessarily donate/accept hydrogen ions
- Fri Dec 07, 2018 10:49 am
- Forum: Bronsted Acids & Bases
- Topic: Exceptions: HSO4- and H2PO4-
- Replies: 4
- Views: 1196
Re: Exceptions: HSO4- and H2PO4-
zoepamonag4C wrote:Is H2PO4- a polyprotic acid? What makes something polyprotic?
Something is polyprotic if it can donate more than one proton (Hydrogen)
- Sat Dec 01, 2018 2:21 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Acid vs base [ENDORSED]
- Replies: 15
- Views: 1561
Re: Acid vs base [ENDORSED]
Lewis acids accept electron pairs and lewis bases are electron donors.
- Sat Dec 01, 2018 2:20 pm
- Forum: Biological Examples
- Topic: Knowledge of Biological Applications for Final
- Replies: 5
- Views: 417
Re: Knowledge of Biological Applications for Final
hemoglobin and chemotherapy drugs are mentioned specifically on the syllabus, so it's probably a good idea to know at least those two examples.
- Sat Dec 01, 2018 2:18 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final Exam
- Replies: 22
- Views: 1659
Re: Final Exam
The final will be cumulative, and i think it will have about equal parts from all parts of the syllabus
- Tue Nov 20, 2018 9:58 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 7th edition problem 2E.5
- Replies: 2
- Views: 273
Re: 7th edition problem 2E.5
It is a trigonal planar arrangement because there are three regions of electron density, however, it has a bent shape because you only take into account the atoms when naming the shape. I believe the question itself asks for the molecular shape, so bent/angular would be the correct answer. Hope that...
- Tue Nov 20, 2018 9:55 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Angles
- Replies: 3
- Views: 435
Re: Bond Angles
I think what the textbook means is that all of the bond angles in SOCl2 are identical, so they all have the same bond angle.
- Tue Nov 20, 2018 9:54 am
- Forum: SI Units, Unit Conversions
- Topic: Significant 0’s [ENDORSED]
- Replies: 8
- Views: 1385
Re: Significant 0’s [ENDORSED]
If you're still having trouble with significant figures, this has been a really helpful resource: https://lavelle.chem.ucla.edu/wp-conten ... OUT_SF.pdf
- Sun Nov 18, 2018 9:33 pm
- Forum: Student Social/Study Group
- Topic: Turning in Homework (Thanksgiving Break)
- Replies: 8
- Views: 845
Re: Turning in Homework (Thanksgiving Break)
I think we're supposed to turn in homework for this week and next week (so 14 problems total) in discussion the week after thanksgiving
- Sun Nov 18, 2018 9:31 pm
- Forum: Properties of Light
- Topic: Test 3
- Replies: 24
- Views: 2196
Re: Test 3
The website says that test 3 will cover "End of Bonding from 3.12 (6 Ed.) and from 2D (7 Ed.); and all of Molecular Shape and Structure (see Syllabus and Outlines for details)"
- Sun Nov 18, 2018 9:29 pm
- Forum: General Science Questions
- Topic: Thanksgiving Week
- Replies: 8
- Views: 944
Re: Thanksgiving Week
We don't have lecture Wednesday, and we have Thursday and Friday off, but I'm pretty sure that discussions are still happening Monday-Wednesday
- Sun Nov 11, 2018 2:03 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Greater polarizability of larger molecules
- Replies: 6
- Views: 1149
Re: Greater polarizability of larger molecules
bigger molecules have more electrons, and therefore more electron shielding so the electrons farther from the nucleus are not as tightly held so they are more easily distorted
- Sun Nov 11, 2018 1:58 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Isoelectronic
- Replies: 14
- Views: 2166
Re: Isoelectronic
Isolelectronic means that two atoms have the same number of valence electrons and the same electron configuration
- Sun Nov 11, 2018 1:48 pm
- Forum: Electronegativity
- Topic: difference in electronegativity
- Replies: 5
- Views: 501
Re: difference in electronegativity
I think for this class at least any time we will need to calculate electronegativity differences the values will be provided, we should just know general trends
- Sun Nov 04, 2018 5:33 pm
- Forum: Trends in The Periodic Table
- Topic: Atomic Radius
- Replies: 4
- Views: 435
Re: Atomic Radius
Atomic radius increases down a group because shells are added with more electrons, so the size of the atom increases. It decreases down a period, though, because the electrons are attracted to the greater number of protons in the nucleus, pulling the electrons in closer.
- Sun Nov 04, 2018 5:29 pm
- Forum: Photoelectric Effect
- Topic: Question on kinetic energy
- Replies: 5
- Views: 733
Re: Question on kinetic energy
Kinetic energy of the ejected photon is given by 1/2mv^2 and the energy of the photon is given by the equation E=hv
- Sun Nov 04, 2018 5:25 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Class Grading
- Replies: 9
- Views: 1154
Re: Class Grading
This is what the syllabus says about grading: "Each test and exam has a total score but is not assigned a grade. Only at the end of the class when the class average score (out of 500 points) is known are final grades assigned. This class does not use a curve. Group learning (Chemistry Community...
- Tue Oct 23, 2018 5:19 pm
- Forum: Administrative Questions and Class Announcements
- Topic: test 2
- Replies: 5
- Views: 713
Re: test 2
No it should just be stuff covered in the quantum world outline. I think this is a pretty good list of most of the stuff you should know: https://lavelle.chem.ucla.edu/wp-conten ... _World.pdf
- Mon Oct 22, 2018 8:14 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Orbitals
- Replies: 2
- Views: 254
Re: Orbitals
I don't think so. On the practice problems in the textbook, it only asks you to draw the s- p- and d- orbitals, so I assume any test would not ask you to draw the f- orbital either since it's pretty complicated.
- Mon Oct 22, 2018 8:11 pm
- Forum: DeBroglie Equation
- Topic: Can't quite get the answer right
- Replies: 2
- Views: 443
Re: Can't quite get the answer right
I noticed that one of your conversion factors is 60sec/1hour when it should be 3600sec/1hour. I would try that and see if it gives you the right answer.
- Mon Oct 22, 2018 11:04 am
- Forum: Administrative Questions and Class Announcements
- Topic: Test On Tuesday
- Replies: 10
- Views: 1072
Re: Test On Tuesday
Professor Lavelle stated that only the material covered in lecture up until last Friday (10/19/18) will be on the test. Since we did not cover periodic trends in lecture, it will not be on the test. If you know everything up until multi-electron atoms, which I believe is section 1E in the seventh e...
- Fri Oct 19, 2018 9:59 am
- Forum: Significant Figures
- Topic: knowing how many sig figs to use
- Replies: 17
- Views: 2210
Re: knowing how many sig figs to use
If you're still confused on sig fig rules, this is a helpful resource for what Dr. Lavelle expects with significant figures: https://lavelle.chem.ucla.edu/wp-conten ... OUT_SF.pdf
- Fri Oct 19, 2018 9:57 am
- Forum: Properties of Light
- Topic: Do I have to memorize the spectrum?
- Replies: 20
- Views: 1695
Re: Do I have to memorize the spectrum?
I don't think you have to memorize the entire spectrum but it would probably be a good idea to have a general sense of what the range for each type of radiation is.
- Fri Oct 19, 2018 9:55 am
- Forum: Administrative Questions and Class Announcements
- Topic: Homework Week 4
- Replies: 4
- Views: 453
Re: Homework Week 4
I think you can do problems from quantum world since that's what the test will be on the same day the homework is due.
- Sun Oct 14, 2018 6:39 pm
- Forum: Einstein Equation
- Topic: Numbers to memorize [ENDORSED]
- Replies: 37
- Views: 4159
Re: Numbers to memorize [ENDORSED]
I think this is the sheet that we will be given with all the constants and equations: https://lavelle.chem.ucla.edu/wp-conten ... ations.pdf
- Thu Oct 11, 2018 1:31 pm
- Forum: Student Social/Study Group
- Topic: Studying techniques
- Replies: 12
- Views: 840
Re: Studying techniques
The things that have helped me the most are doing lots of problems from the textbook and doing the video modules that Dr. Lavelle has on his website, including the post and pre-assessments. The examples in the textbook are also a great resource if you are still feeling unsure about certain topics.
- Thu Oct 11, 2018 10:48 am
- Forum: Balancing Chemical Reactions
- Topic: Test 1
- Replies: 6
- Views: 2791
Re: Test 1
Definitely show enough work to get points, or partial credit if you mess up somewhere. Don't worry about being overly thorough though because you do want to make sure that you finish the test in time.
- Wed Oct 10, 2018 10:10 am
- Forum: Significant Figures
- Topic: Calculators
- Replies: 20
- Views: 1930
Re: Calculators
I would buy a calculator to use on the test because you will need it for calculations like molar mass and dimensional analysis calculations which can be tricky and time consuming to do by hand. Calculators were not provided during my test, but it might be worth it to double check with your TA.
- Wed Oct 03, 2018 3:11 pm
- Forum: Balancing Chemical Reactions
- Topic: Combustion Reactions.
- Replies: 8
- Views: 3015
Re: Combustion Reactions.
In combustion reactions, the reactants are always O2 and the hydrocarbon and the products are CO2 and H2O.
- Wed Oct 03, 2018 3:08 pm
- Forum: Student Social/Study Group
- Topic: HW Schedule?
- Replies: 7
- Views: 975
Re: HW Schedule?
I don't think that each outline corresponds to a week, but either way I think we'll be told when we switch to subject matter from a different outline/section.
- Wed Oct 03, 2018 3:06 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Coefficients and Subscripts
- Replies: 4
- Views: 1633
Re: Coefficients and Subscripts
Hi! You don't multiply the subscript because it refers to how many atoms of that element are in the molecule not how many moles of the molecule are necessary in the equation. If you changed the subscript it would consequently change the molecular composition and the molecule would become a different...