Search found 62 matches

by Mikka Hoffman 1C
Sun Mar 17, 2019 4:15 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Effect of increased concentration on equilibrium
Replies: 9
Views: 151

Re: Effect of increased concentration on equilibrium

The reactions will form products to restore equilibrium
by Mikka Hoffman 1C
Sun Mar 17, 2019 4:12 pm
Forum: Balancing Redox Reactions
Topic: Triprotic
Replies: 7
Views: 258

Re: Triprotic

Yes, a triprotic acid has 3 protons, or 3 hydrogens
by Mikka Hoffman 1C
Sat Mar 16, 2019 12:15 am
Forum: *Enzyme Kinetics
Topic: sig figs on the final
Replies: 2
Views: 33

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.
by Mikka Hoffman 1C
Sun Mar 10, 2019 10:01 pm
Forum: Student Social/Study Group
Topic: Final
Replies: 24
Views: 416

Re: Final

Here's a link to the final review session information: https://lavelle.chem.ucla.edu/wp-conten ... ns_14B.pdf
by Mikka Hoffman 1C
Sun Mar 10, 2019 9:55 pm
Forum: Administrative Questions and Class Announcements
Topic: Final Questions
Replies: 10
Views: 156

Re: Final Questions

I would expect around 8 questions, but with multiple parts similar to the format of the midterm.
by Mikka Hoffman 1C
Sun Mar 10, 2019 9:55 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Final Exam
Replies: 23
Views: 188

Re: Final Exam

yes, the final covers everything we've covered in class so chemical equilibrium will definitely show up.
by Mikka Hoffman 1C
Wed Feb 27, 2019 7:07 pm
Forum: Ideal Gases
Topic: Q and K
Replies: 13
Views: 148

Re: Q and K

Q can be calculated at any point in the reaction, whereas K is only calculated at equilibrium
by Mikka Hoffman 1C
Wed Feb 27, 2019 10:28 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Question for Test 2
Replies: 4
Views: 72

Re: Question for Test 2

yes you should probably know it since it was covered in lecture last week.
by Mikka Hoffman 1C
Wed Feb 27, 2019 10:26 am
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: n
Replies: 8
Views: 83

Re: n

n in this equation is the moles of electrons transferred in your balanced redox reaction
by Mikka Hoffman 1C
Sun Feb 24, 2019 9:31 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: n value
Replies: 11
Views: 81

Re: n value

the textbook says that n in this equation is the number of miles of electrons transferred in the reaction.
by Mikka Hoffman 1C
Sun Feb 24, 2019 9:28 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagrams
Replies: 2
Views: 29

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.
by Mikka Hoffman 1C
Sun Feb 24, 2019 9:25 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagram Lines
Replies: 3
Views: 27

Re: Cell Diagram Lines

One vertical line represents interface between phases while two vertical lines represents a salt bridge.
by Mikka Hoffman 1C
Sun Feb 17, 2019 11:12 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: Midterm Grades
Replies: 35
Views: 422

Re: Midterm Grades

Most likely we will get the midterms back this coming week in our discussion sections
by Mikka Hoffman 1C
Sun Feb 17, 2019 11:09 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: HW for W7
Replies: 7
Views: 74

Re: HW for W7

I think Gibbs free energy is fine as long as it's stuff from after the midterm
by Mikka Hoffman 1C
Sun Feb 17, 2019 11:07 pm
Forum: Student Social/Study Group
Topic: Test
Replies: 17
Views: 281

Re: Test

Dr. Lavelle's website says "Test 2 covers all topics on Gibbs free energy and electrochemistry up to the Nernst equation"
by Mikka Hoffman 1C
Sun Feb 10, 2019 9:21 pm
Forum: Calculating Work of Expansion
Topic: Derivatives and Integrals
Replies: 5
Views: 50

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.
by Mikka Hoffman 1C
Sun Feb 10, 2019 9:18 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Study Guides
Replies: 15
Views: 263

Re: Study Guides

Lyndon made one that you can find if you search "hotdog" on chemistry community.
by Mikka Hoffman 1C
Sun Feb 10, 2019 9:16 pm
Forum: General Science Questions
Topic: Midterm Formulas
Replies: 1
Views: 63

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
by Mikka Hoffman 1C
Mon Feb 04, 2019 10:05 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Midterm [ENDORSED]
Replies: 48
Views: 767

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
by Mikka Hoffman 1C
Mon Feb 04, 2019 10:03 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Isolated System (Water bottle)
Replies: 6
Views: 87

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
by Mikka Hoffman 1C
Mon Feb 04, 2019 10:02 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Cup of Tea
Replies: 17
Views: 215

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.
by Mikka Hoffman 1C
Sun Jan 27, 2019 3:36 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Calculating Q
Replies: 11
Views: 119

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.
by Mikka Hoffman 1C
Sun Jan 27, 2019 3:34 pm
Forum: Phase Changes & Related Calculations
Topic: Modules
Replies: 17
Views: 176

Re: Modules

They're not mandatory, but they are very helpful especially when studying for tests or the midterm/final.
by Mikka Hoffman 1C
Sun Jan 27, 2019 3:31 pm
Forum: Phase Changes & Related Calculations
Topic: Week 4 Homework
Replies: 12
Views: 162

Re: Week 4 Homework

Yes, I think as long as it's from Thermochemistry (outline 3) you're fine.
by Mikka Hoffman 1C
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: 40

Re: Test topics for next week

Dr. Lavelle's website says "Test 1 covers Equilibrium and Acid & Base Equilibria"
by Mikka Hoffman 1C
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: 59

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.
by Mikka Hoffman 1C
Wed Jan 16, 2019 10:47 pm
Forum: Administrative Questions and Class Announcements
Topic: Number of questions on test one [ENDORSED]
Replies: 39
Views: 17364

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...
by Mikka Hoffman 1C
Sun Jan 13, 2019 7:39 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Calculating Q
Replies: 7
Views: 56

Re: Calculating Q

Q is calculated the same way as K, so you will always have products over reactants
by Mikka Hoffman 1C
Sun Jan 13, 2019 7:38 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Example in Class
Replies: 7
Views: 103

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
by Mikka Hoffman 1C
Sun Jan 13, 2019 7:37 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Kp Units
Replies: 6
Views: 75

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
by Mikka Hoffman 1C
Fri Dec 07, 2018 11:08 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular shape
Replies: 3
Views: 29

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.
by Mikka Hoffman 1C
Fri Dec 07, 2018 10:59 am
Forum: Amphoteric Compounds
Topic: Amphiprotic vs. amphoteric
Replies: 3
Views: 71

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
by Mikka Hoffman 1C
Fri Dec 07, 2018 10:49 am
Forum: Bronsted Acids & Bases
Topic: Exceptions: HSO4- and H2PO4-
Replies: 4
Views: 56

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)
by Mikka Hoffman 1C
Sat Dec 01, 2018 2:21 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Acid vs base [ENDORSED]
Replies: 15
Views: 218

Re: Acid vs base [ENDORSED]

Lewis acids accept electron pairs and lewis bases are electron donors.
by Mikka Hoffman 1C
Sat Dec 01, 2018 2:20 pm
Forum: Biological Examples
Topic: Knowledge of Biological Applications for Final
Replies: 5
Views: 73

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.
by Mikka Hoffman 1C
Sat Dec 01, 2018 2:18 pm
Forum: Administrative Questions and Class Announcements
Topic: Final Exam
Replies: 22
Views: 424

Re: Final Exam

The final will be cumulative, and i think it will have about equal parts from all parts of the syllabus
by Mikka Hoffman 1C
Tue Nov 20, 2018 9:58 am
Forum: Determining Molecular Shape (VSEPR)
Topic: 7th edition problem 2E.5
Replies: 2
Views: 44

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...
by Mikka Hoffman 1C
Tue Nov 20, 2018 9:55 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 3
Views: 44

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.
by Mikka Hoffman 1C
Tue Nov 20, 2018 9:54 am
Forum: SI Units, Unit Conversions
Topic: Significant 0’s
Replies: 4
Views: 156

Re: Significant 0’s

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
by Mikka Hoffman 1C
Sun Nov 18, 2018 9:33 pm
Forum: Student Social/Study Group
Topic: Turning in Homework (Thanksgiving Break)
Replies: 8
Views: 185

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
by Mikka Hoffman 1C
Sun Nov 18, 2018 9:31 pm
Forum: Properties of Light
Topic: Test 3
Replies: 24
Views: 452

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)"
by Mikka Hoffman 1C
Sun Nov 18, 2018 9:29 pm
Forum: General Science Questions
Topic: Thanksgiving Week
Replies: 8
Views: 251

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
by Mikka Hoffman 1C
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: 67

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
by Mikka Hoffman 1C
Sun Nov 11, 2018 1:58 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Isoelectronic
Replies: 14
Views: 447

Re: Isoelectronic

Isolelectronic means that two atoms have the same number of valence electrons and the same electron configuration
by Mikka Hoffman 1C
Sun Nov 11, 2018 1:48 pm
Forum: Electronegativity
Topic: difference in electronegativity
Replies: 5
Views: 91

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
by Mikka Hoffman 1C
Sun Nov 04, 2018 5:33 pm
Forum: Trends in The Periodic Table
Topic: Atomic Radius
Replies: 4
Views: 72

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.
by Mikka Hoffman 1C
Sun Nov 04, 2018 5:29 pm
Forum: Photoelectric Effect
Topic: Question on kinetic energy
Replies: 5
Views: 171

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
by Mikka Hoffman 1C
Sun Nov 04, 2018 5:25 pm
Forum: Administrative Questions and Class Announcements
Topic: Class Grading
Replies: 9
Views: 310

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...
by Mikka Hoffman 1C
Tue Oct 23, 2018 5:19 pm
Forum: Administrative Questions and Class Announcements
Topic: test 2
Replies: 5
Views: 216

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
by Mikka Hoffman 1C
Mon Oct 22, 2018 8:14 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Orbitals
Replies: 2
Views: 41

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.
by Mikka Hoffman 1C
Mon Oct 22, 2018 8:11 pm
Forum: DeBroglie Equation
Topic: Can't quite get the answer right
Replies: 2
Views: 73

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.
by Mikka Hoffman 1C
Mon Oct 22, 2018 11:04 am
Forum: Administrative Questions and Class Announcements
Topic: Test On Tuesday
Replies: 10
Views: 399

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...
by Mikka Hoffman 1C
Fri Oct 19, 2018 9:59 am
Forum: Significant Figures
Topic: knowing how many sig figs to use
Replies: 17
Views: 461

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
by Mikka Hoffman 1C
Fri Oct 19, 2018 9:57 am
Forum: Properties of Light
Topic: Do I have to memorize the spectrum?
Replies: 20
Views: 295

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.
by Mikka Hoffman 1C
Fri Oct 19, 2018 9:55 am
Forum: Administrative Questions and Class Announcements
Topic: Homework Week 4
Replies: 4
Views: 76

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.
by Mikka Hoffman 1C
Sun Oct 14, 2018 6:39 pm
Forum: Einstein Equation
Topic: Numbers to memorize
Replies: 24
Views: 533

Re: Numbers to memorize

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
by Mikka Hoffman 1C
Thu Oct 11, 2018 1:31 pm
Forum: Student Social/Study Group
Topic: Studying techniques
Replies: 12
Views: 234

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.
by Mikka Hoffman 1C
Thu Oct 11, 2018 10:48 am
Forum: Balancing Chemical Reactions
Topic: Test 1
Replies: 6
Views: 190

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.
by Mikka Hoffman 1C
Wed Oct 10, 2018 10:10 am
Forum: Significant Figures
Topic: Calculators
Replies: 16
Views: 383

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.
by Mikka Hoffman 1C
Wed Oct 03, 2018 3:11 pm
Forum: Balancing Chemical Reactions
Topic: Combustion Reactions.
Replies: 8
Views: 196

Re: Combustion Reactions.

In combustion reactions, the reactants are always O2 and the hydrocarbon and the products are CO2 and H2O.
by Mikka Hoffman 1C
Wed Oct 03, 2018 3:08 pm
Forum: Student Social/Study Group
Topic: HW Schedule?
Replies: 7
Views: 237

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.
by Mikka Hoffman 1C
Wed Oct 03, 2018 3:06 pm
Forum: Molarity, Solutions, Dilutions
Topic: Coefficients and Subscripts
Replies: 4
Views: 84

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...

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