Search found 58 matches
- Sun Mar 17, 2019 12:53 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Test 2 Question 5
- Replies: 5
- Views: 910
Re: Test 2 Question 5
u guys reply with different answers. did lavelle ever post the solution? where can i find the solution?
- Sat Mar 09, 2019 5:26 pm
- Forum: Zero Order Reactions
- Topic: initial concentration
- Replies: 6
- Views: 664
Re: initial concentration
so is it okay to assume infinite concentration of initial reactants?
- Sat Mar 09, 2019 5:25 pm
- Forum: Zero Order Reactions
- Topic: Zero order
- Replies: 10
- Views: 1673
Re: Zero order
i am also confused about this... what do the different orders actually mean?
- Sat Mar 09, 2019 5:23 pm
- Forum: *Electrophiles
- Topic: what is going to be on the final? [ENDORSED]
- Replies: 12
- Views: 2718
Re: what is going to be on the final? [ENDORSED]
wait have we already gone over the ochem topics?
- Fri Mar 01, 2019 1:12 am
- Forum: Phase Changes & Related Calculations
- Topic: reversible processes and equilibrium
- Replies: 4
- Views: 502
Re: reversible processes and equilibrium
to answer your question, yes
- Fri Mar 01, 2019 1:02 am
- Forum: Phase Changes & Related Calculations
- Topic: Phase Changes
- Replies: 11
- Views: 1445
Re: Phase Changes
It appeared on the 2019 test so I advise future students to learn it well beforehand.
- Fri Mar 01, 2019 12:55 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Does anyone know if test 2 will be curved?
- Replies: 15
- Views: 3025
Does anyone know if test 2 will be curved?
:') i really hope it will be
- Thu Feb 21, 2019 1:17 am
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: 7th edition 4I. 9
- Replies: 3
- Views: 556
Re: 7th edition 4I. 9
Calculate using two separate formulas given in lecture then compare the entropy changes
- Thu Feb 21, 2019 1:15 am
- Forum: Administrative Questions and Class Announcements
- Topic: DOWNLOAD SESSION WORKSHEETS HERE - Sun 7-9PM (Karen)
- Replies: 179
- Views: 24136
Re: DOWNLOAD SESSION WORKSHEETS HERE - Sun 7-9PM (Karen)
This is so helpful. Are the attachments basically study guides?
- Thu Feb 21, 2019 1:13 am
- Forum: Ideal Gases
- Topic: Reading the textbook
- Replies: 262
- Views: 152010
Re: Reading the textbook
Although reading the text book helps, I think simply completing all homework questions and attending lecture and discussion is sufficient to fully understand the course material, to be honest.
- Fri Feb 15, 2019 10:30 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Adding reaction entropies
- Replies: 8
- Views: 895
Re: Adding reaction entropies
It is allowed because entropy is a state function. A lot of what we are working on are state functions (like enthalpy, gibbs free energy), except for work and heat.
- Fri Feb 15, 2019 10:24 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Midterm Prep Question
- Replies: 3
- Views: 406
Re: Midterm Prep Question
You calculate he entropies of the change in temperature and the change in pressure separately and then add them up, since entropy is a state function.
- Fri Feb 15, 2019 10:15 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: System and surroundings
- Replies: 4
- Views: 609
Re: System and surroundings
Recall that the change in entropy of the universe is equal to the sum of the change in entropy of the surrounding and the system. And in a reversible reaction, the total change in entropy in the universe is 0, and thus the change in entropy of the surrounding and the system have to equal.
- Wed Feb 06, 2019 9:54 pm
- Forum: Student Social/Study Group
- Topic: New to Lavelle
- Replies: 32
- Views: 5323
Re: New to Lavelle
Doing all of the homework problems (not just the 7, but every one listed) helps me the most. His tests are pretty similar to the homework problems sometimes even easier.
- Wed Feb 06, 2019 9:52 pm
- Forum: Student Social/Study Group
- Topic: Absent on 1/30; in need of notes
- Replies: 4
- Views: 500
Re: Absent on 1/30; in need of notes
you can ask me for notes :) xuj67497@g.ucla.edu
- Wed Feb 06, 2019 9:51 pm
- Forum: Student Social/Study Group
- Topic: Note Taking
- Replies: 145
- Views: 17334
Re: Note Taking
You can also use an ipad to take notes. Goodnotes 4 or 5 are both really good for note taking and organization.
- Sun Feb 03, 2019 3:29 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: What not to count
- Replies: 9
- Views: 915
Re: What not to count
You should just ignore everything thats not in a gaseous state
- Wed Jan 30, 2019 10:41 pm
- Forum: Ideal Gases
- Topic: breaking bond - heat released and gained
- Replies: 5
- Views: 911
Re: breaking bond - heat released and gained
from what i learned in LS i think when u break a bond u release energy (so youre right). For example breaking off a phosphate from ATP will result in energy release.
- Wed Jan 30, 2019 10:21 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Advice from a Medical Student [ENDORSED]
- Replies: 297
- Views: 423063
Re: Advice from a Medical Student [ENDORSED]
thank you so much!! that was actually very helpful considering how stressful the process is.
- Wed Jan 30, 2019 10:20 pm
- Forum: Ideal Gases
- Topic: atm vs. bar?
- Replies: 25
- Views: 2972
Re: atm vs. bar?
On the test I used bar and it was fine
- Fri Jan 25, 2019 10:00 pm
- Forum: Ideal Gases
- Topic: Ideal Gas Law
- Replies: 7
- Views: 763
Re: Ideal Gas Law
for conversion between concentration and pressure? I'm not really sure.
- Fri Jan 25, 2019 9:56 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Increase in Volume Effect on Equilibrium
- Replies: 6
- Views: 1545
- Fri Jan 25, 2019 9:53 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Increasing Pressure
- Replies: 3
- Views: 384
Re: Increasing Pressure
an increase in pressure would shift the reaction towards the side with less moles.
- Sun Jan 20, 2019 8:30 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Is it an acid or a base?
- Replies: 8
- Views: 715
Re: Is it an acid or a base?
You can also look for any part of the compound that has a strong dipole moment, bc that can usually tell you where an extra hydrogen can go
- Sun Jan 20, 2019 8:20 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: The Conjugate Seesaw
- Replies: 13
- Views: 998
Re: The Conjugate Seesaw
Because Ka and Kb have inverse relationships since Kw is a constant
- Sun Jan 20, 2019 8:16 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Equilibrium and Volume
- Replies: 2
- Views: 144
Re: Equilibrium and Volume
wait why does the first part happen?
- Sat Jan 12, 2019 6:49 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Equilibrium constant
- Replies: 4
- Views: 401
Re: Equilibrium constant
More reactants yields more products until K reaches its original value again.
- Sat Jan 12, 2019 6:47 pm
- Forum: Ideal Gases
- Topic: K and Q
- Replies: 7
- Views: 513
Re: K and Q
K is used for the exact equilibrium state and Q is used for anytime during the reaction. When they are not exactly the same then the current reaction is leaning one direction or the other.
- Sat Jan 12, 2019 6:45 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Heterogeneous and homogeneous equilibria [ENDORSED]
- Replies: 8
- Views: 769
Re: Heterogeneous and homogeneous equilibria [ENDORSED]
Is heterogenous equilibria just a reaction at equilibrium that involves more than 1 phase?
- Sat Dec 08, 2018 1:40 pm
- Forum: Calculating the pH of Salt Solutions
- Topic: 6d11 7th edition
- Replies: 3
- Views: 628
Re: 6d11 7th edition
Me too. I hope it's not on the final.
- Sat Dec 08, 2018 1:35 pm
- Forum: Naming
- Topic: confusion name to formula
- Replies: 4
- Views: 523
Re: confusion name to formula
The "ate" refers to only the anion complex. But the overall charge should always be zero.
- Sat Dec 08, 2018 1:32 pm
- Forum: Naming
- Topic: order of ligand name
- Replies: 5
- Views: 719
Re: order of ligand name
I think in class Dr. Lavelle said to just name them in alphabetical order.
- Sat Dec 08, 2018 1:30 pm
- Forum: Naming
- Topic: naming compounds
- Replies: 6
- Views: 612
Re: naming compounds
Do we have to memorize the polydentates for the final?
- Sat Dec 08, 2018 1:21 pm
- Forum: Amphoteric Compounds
- Topic: 7th edition 6A.17
- Replies: 3
- Views: 367
Re: 7th edition 6A.17
I think you can identify amphoteric compounds by just memorizing them. Basic oxides are always bound to metals, and acidic oxides alway bound to non-metals. But amphoteric oxides are usually formed by the elements in or close to the diagonal line of metalloids.
- Sun Dec 02, 2018 5:53 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: AX2E2
- Replies: 14
- Views: 4586
Re: AX2E2
Because the lone pairs are more negative than an atom, it pushes harder on the two bonded atoms, thus making the angle between them less than 109.5.
- Sun Dec 02, 2018 5:51 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Dipole moment
- Replies: 7
- Views: 722
Re: Dipole moment
When the electronegativities of two atoms bonded are very different, the molecule will have dipole moment
- Sun Dec 02, 2018 5:49 pm
- Forum: Hybridization
- Topic: Hybridization of pi bonds
- Replies: 3
- Views: 410
Re: Hybridization of pi bonds
Hybridized orbitals only occur for sigma bonds. Pi bonds take place in the leftover P orbitals.
- Sun Nov 18, 2018 5:06 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Lone Pairs
- Replies: 8
- Views: 2743
Re: Lone Pairs
Lone pairs are considered to be more repulsive (more negative) and it pushes on the bound atoms.
- Sun Nov 18, 2018 4:54 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Square Planar vs Tetrahedral
- Replies: 8
- Views: 2442
Re: Square Planar vs Tetrahedral
So does square planar molecules have AX4E2 and tetrahedral just Ax4?
- Sun Nov 18, 2018 4:52 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Angular vs Bent
- Replies: 4
- Views: 495
Re: Angular vs Bent
They are the same thing. They both describe central molecules with two atoms bound and one pair of lone pair electrons.
- Sun Nov 11, 2018 9:53 pm
- Forum: Resonance Structures
- Topic: Drawing resonance
- Replies: 17
- Views: 1891
Re: Drawing resonance
Wait how do you know if there will be resonance structures on a molecule?
- Sun Nov 11, 2018 9:41 pm
- Forum: Dipole Moments
- Topic: Dipole Moments
- Replies: 4
- Views: 375
Re: Dipole Moments
Basically molecules with atoms that differ largely in terms of electronegativity should have dipole moments
- Sun Nov 11, 2018 9:38 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Stable Condition
- Replies: 8
- Views: 2572
Re: Stable Condition
I might be wrong but I think Dr. Lavelle said that the molecule is the most stable when the FC is equal to 0
- Fri Nov 02, 2018 8:26 pm
- Forum: Photoelectric Effect
- Topic: Chem Test 2, #5 b
- Replies: 4
- Views: 639
Re: Chem Test 2, #5 b
I got credit by saying that atoms have discrete energy levels. I hope that helps
- Fri Nov 02, 2018 8:21 pm
- Forum: Ionic & Covalent Bonds
- Topic: Midterm study
- Replies: 7
- Views: 843
Re: Midterm study
Is there a face book group chat?
- Fri Nov 02, 2018 8:18 pm
- Forum: Ionic & Covalent Bonds
- Topic: Non-polar and Polar Covalent Bonds
- Replies: 3
- Views: 476
Re: Non-polar and Polar Covalent Bonds
If a covalently bonded molecule is symmetrical it is polar.
- Sun Oct 28, 2018 1:24 pm
- Forum: Photoelectric Effect
- Topic: Work Function
- Replies: 14
- Views: 2264
Re: Work Function
Is the work function the same as the threshold energy?
- Sun Oct 28, 2018 1:22 pm
- Forum: Photoelectric Effect
- Topic: Test 2
- Replies: 16
- Views: 1183
Re: Test 2
Does anyone know if Test 2 will be curved?
- Sun Oct 28, 2018 1:21 pm
- Forum: Photoelectric Effect
- Topic: UA practice problem frequency of light
- Replies: 3
- Views: 889
Re: UA practice problem frequency of light
Can someone explain what a work function is? I think i got that wrong on the test because i thought a work function was work as a function of time.
- Fri Oct 19, 2018 8:57 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Equation
- Replies: 6
- Views: 684
Re: Equation
Is there a reason why they use pie?
- Fri Oct 19, 2018 8:55 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Nodal Planes [ENDORSED]
- Replies: 4
- Views: 756
Re: Nodal Planes [ENDORSED]
I think it’s just where you’ll never find electrons
- Fri Oct 19, 2018 8:54 pm
- Forum: Properties of Electrons
- Topic: Questions about the energy level [ENDORSED]
- Replies: 3
- Views: 459
Questions about the energy level [ENDORSED]
Can someone explain the relationship between energy level (n) and energy?
I think they’re inversely related but I’m not sure how it works conceptually..
I think they’re inversely related but I’m not sure how it works conceptually..
- Sat Oct 13, 2018 9:03 pm
- Forum: Balancing Chemical Reactions
- Topic: Test 1 and Future Tests
- Replies: 5
- Views: 787
Re: Test 1 and Future Tests
Anton said to always write all the steps out so if your final answer is incorrect, he can still trace back and give you partial points.
- Sat Oct 13, 2018 9:01 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: diatomic elements
- Replies: 12
- Views: 9938
Re: diatomic elements
Does anyone know what order to put the elements in when writing an empirical formula?
- Sat Oct 13, 2018 8:59 pm
- Forum: Significant Figures
- Topic: sig fig calculations
- Replies: 3
- Views: 659
Re: sig fig calculations
Do you use the least number of significant digits from the given values for your answer?
- Fri Oct 05, 2018 12:22 am
- Forum: General Science Questions
- Topic: Rusty on High School Chem [ENDORSED]
- Replies: 347
- Views: 442785
Re: Rusty on High School Chem [ENDORSED]
I took regular chemistry in my sophomore year and here I am three years later taking 14A. I've been watching crash course videos, and that has helped a ton.
- Fri Oct 05, 2018 12:09 am
- Forum: Significant Figures
- Topic: sig figs urgent question!
- Replies: 12
- Views: 2202
Re: sig figs urgent question!
1.001 would have 4 significant figures. As the last post says, it depends on whether there's a decimal or not. For example, 100 has only 1 significant figure, but 100. has 3.
- Fri Oct 05, 2018 12:01 am
- Forum: Administrative Questions and Class Announcements
- Topic: Advice from a Medical Student [ENDORSED]
- Replies: 297
- Views: 423063
Re: Advice from a Medical Student [ENDORSED]
Asheley thank you so much!
I was wondering when pre-med students should start studying for the MCAT? Also, what kind of chemistry is on the test?
I was wondering when pre-med students should start studying for the MCAT? Also, what kind of chemistry is on the test?