Search found 95 matches

by Allan Nguyen 2G
Fri Feb 26, 2021 7:21 pm
Forum: Balancing Redox Reactions
Topic: Sapling #18 for Wk 7 and 8
Replies: 3
Views: 38

Sapling #18 for Wk 7 and 8

Hello, can someone help with #18? I am not sure how to get started with this problem. Thanks in advance!
by Allan Nguyen 2G
Fri Feb 26, 2021 2:56 am
Forum: Student Social/Study Group
Topic: Anxiety
Replies: 53
Views: 314

Re: Anxiety

This probably isn't the best advice but I literally just study to the point I am no longer nervous. I kinda just do as many practice problems as I can and it just makes more confident in doing chemistry problems in regards to future exams.
by Allan Nguyen 2G
Wed Feb 24, 2021 10:04 pm
Forum: Administrative Questions and Class Announcements
Topic: Chem 14 B Final
Replies: 34
Views: 150

Re: Chem 14 B Final

I'm assuming it's going to be just like last quarter for Lavelle's 14A class where the final was cumulative and the amount of questions for each section was based off of the amount of time we spent on each unit.
by Allan Nguyen 2G
Wed Feb 24, 2021 8:10 pm
Forum: Student Social/Study Group
Topic: Balance / Self Care Tips
Replies: 41
Views: 124

Re: Balance / Self Care Tips

Keeping a to-do list for the day really keeps you on top of everything. Ever since I starting making a to-do list for my daily tasks, it's been much easier managing time for each task for the day.
by Allan Nguyen 2G
Wed Feb 24, 2021 9:21 am
Forum: Balancing Redox Reactions
Topic: Sapling #3 for Wk 7 and 8
Replies: 3
Views: 20

Sapling #3 for Wk 7 and 8

Hello, can somebody help me with this question? Thanks in advance!
by Allan Nguyen 2G
Fri Feb 19, 2021 9:13 pm
Forum: Student Social/Study Group
Topic: Post Midterm 2 De-stressing
Replies: 86
Views: 233

Re: Post Midterm 2 De-stressing

I'm probably just going to watch some shows and play video games. Perfect way to destress in my opinion.
by Allan Nguyen 2G
Fri Feb 19, 2021 9:12 pm
Forum: Student Social/Study Group
Topic: Classes for next quarter?
Replies: 131
Views: 430

Re: Classes for next quarter?

I'll be taking Chem 14C, LS 7B and Psych 10
by Allan Nguyen 2G
Fri Feb 19, 2021 7:38 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gas Constant R
Replies: 41
Views: 65

Re: Gas Constant R

It really just depends what you want your answer to end in. 8.314 is typically used when you want your answer to end in joules.
by Allan Nguyen 2G
Thu Feb 18, 2021 8:06 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Adiabatic
Replies: 25
Views: 59

Re: Adiabatic

I found this Chemistry Community post from Lavelle in which he posted a list of thermodynamic definitions. https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=128&t=9661 Adiabatic (also called adiabatically isolated system) An adiabatically isolated system has only adiabatic boundary sectors. En...
by Allan Nguyen 2G
Wed Feb 17, 2021 9:12 pm
Forum: Administrative Questions and Class Announcements
Topic: MIDTERM 2
Replies: 9
Views: 83

Re: MIDTERM 2

It's the lectures from weeks 4-6
by Allan Nguyen 2G
Fri Feb 12, 2021 10:50 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: q equation
Replies: 21
Views: 53

Re: q equation

Both solve for q and m or n in the equation represents specific heat capacity or molar heat capacity.
by Allan Nguyen 2G
Fri Feb 12, 2021 9:12 pm
Forum: Student Social/Study Group
Topic: Thoughts on Upcoming Midterm 2
Replies: 41
Views: 225

Re: Thoughts on Upcoming Midterm 2

I've been feeling nervous myself. I feel like the thermodynamics section ramped up so much in comparison to previous units. We still have a week left till the midterm though so I hope everyone is confident by then.
by Allan Nguyen 2G
Fri Feb 12, 2021 5:07 pm
Forum: Administrative Questions and Class Announcements
Topic: UA Sessions: Midterm 2 Review
Replies: 13
Views: 70

Re: UA Sessions: Midterm 2 Review

I remember some UA sessions where they did midterm review for the first hour and new material for the second half.
by Allan Nguyen 2G
Fri Feb 12, 2021 6:34 am
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Residual entropy
Replies: 4
Views: 24

Re: Residual entropy

I believe it'd be N2O since it can have multiple orientations and also has resonance. Also, I found this other post on Chemistry Community to be very helpful in relation to your question. https://lavelle.chem.ucla.edu/forum/viewtopic.php?t=10290 To calculate the residual entropy, you need to know ho...
by Allan Nguyen 2G
Wed Feb 10, 2021 4:03 am
Forum: Student Social/Study Group
Topic: Points needed to pass?
Replies: 54
Views: 200

Re: Points needed to pass?

From what I've heard for this class, getting more than 200 points lets you pass the class. Basically, a 50% in this class is a passing grade.
by Allan Nguyen 2G
Sun Feb 07, 2021 1:05 am
Forum: Student Social/Study Group
Topic: Favorite TV shows
Replies: 189
Views: 1214

Re: Favorite TV shows

I've been watching Neon Genesis Evangelion. It's such a classic show.
by Allan Nguyen 2G
Sun Feb 07, 2021 12:46 am
Forum: Calculating Work of Expansion
Topic: Sapling #14 for Wk 3 and 4
Replies: 12
Views: 67

Sapling #14 for Wk 3 and 4

Hello, can someone help me with this problem for Sapling? Thanks in advance!
by Allan Nguyen 2G
Sat Feb 06, 2021 7:21 pm
Forum: Administrative Questions and Class Announcements
Topic: Chemistry Community Posts
Replies: 17
Views: 57

Re: Chemistry Community Posts

It depends on your TA but I heard from others that you can still get chem community points back if you make up for the posts that you missed for a certain week.
by Allan Nguyen 2G
Fri Feb 05, 2021 1:07 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Work
Replies: 39
Views: 106

Re: Work

Hello, similar to what everyone said, when there is a negative value for work that means the work is done by the system whereas when the value for w is positive work is being done on the system by the surroundings. I found this video by the Organic Chemistry Tutor to be very helpful! https://www.you...
by Allan Nguyen 2G
Thu Feb 04, 2021 11:42 pm
Forum: General Science Questions
Topic: Tips
Replies: 24
Views: 77

Re: Tips

I know that this is a slightly different question, but I would also really appreciate any tips that you guys have for studying for the midterms or studying for this class in general. Similar to what others have said, I've found attending UA sessions, textbook and Sapling to work really well. Also, ...
by Allan Nguyen 2G
Sat Jan 30, 2021 5:33 pm
Forum: Administrative Questions and Class Announcements
Topic: Chem 14C Spring Quarter
Replies: 11
Views: 114

Re: Chem 14C Spring Quarter

It's seems like the only professor for 14C is Castillo
by Allan Nguyen 2G
Thu Jan 28, 2021 12:52 am
Forum: Polyprotic Acids & Bases
Topic: 6E.1 for Textbook
Replies: 2
Views: 25

Re: 6E.1 for Textbook

AdilaAhmed3I wrote:They simply factored out that negative. Your set up is correct and will get the same answer

Oh I see, how did I not see that loll
by Allan Nguyen 2G
Thu Jan 28, 2021 12:03 am
Forum: Polyprotic Acids & Bases
Topic: 6E.1 for Textbook
Replies: 2
Views: 25

6E.1 for Textbook

Hello, this is a really minor problem but for 6E.1 in the textbook, the answer in the solutions manual puts in the c value for the quadratic equation as positive. Are you supposed to do that or am I doing something wrong? I put a screenshot of my work and the answer in the solution manual for compar...
by Allan Nguyen 2G
Wed Jan 27, 2021 11:16 pm
Forum: Administrative Questions and Class Announcements
Topic: Lecture Content for MT1
Replies: 4
Views: 21

Re: Lecture Content for MT1

I believe it's up to last Friday's lecture, so that would be Lecture #8 (Fri, 01/22/2021)
by Allan Nguyen 2G
Sat Jan 23, 2021 10:10 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: pKa and Ka
Replies: 27
Views: 80

Re: pKa and Ka

The smaller the pka and higher the Ka the stronger the acid and vice versa the higher the pka and smaller the Ka the weaker the acid.
by Allan Nguyen 2G
Sat Jan 23, 2021 10:09 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Solids in Ice Tables
Replies: 11
Views: 50

Re: Solids in Ice Tables

Anything solid or liquid is never included in an ice table.
by Allan Nguyen 2G
Fri Jan 22, 2021 1:05 am
Forum: Student Social/Study Group
Topic: Calculators
Replies: 34
Views: 119

Re: Calculators

I was able to use a graphing calculator last quarter for Lavelle's Chem 14A class so it should be okay.
by Allan Nguyen 2G
Thu Jan 21, 2021 9:26 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Studying for Midterm #1
Replies: 63
Views: 181

Re: Studying for Midterm #1

Textbook problems and UA sessions are your go to for studying in this class. Exposing yourself to different problems just helps you in the long run with exams.
by Allan Nguyen 2G
Thu Jan 21, 2021 12:18 am
Forum: Phase Changes & Related Calculations
Topic: Vapor vs gas
Replies: 92
Views: 239

Re: Vapor vs gas

They're essentially the same thing
by Allan Nguyen 2G
Sat Jan 16, 2021 8:48 pm
Forum: Ideal Gases
Topic: Units of Temperature
Replies: 82
Views: 354

Re: Units of Temperature

For chemistry problems, I'm pretty sure you'd always use kelvin.
by Allan Nguyen 2G
Fri Jan 15, 2021 9:53 pm
Forum: Administrative Questions and Class Announcements
Topic: Exam Format
Replies: 15
Views: 102

Re: Exam Format

So we have just the 50 minute lecture time for the exam? And about how long did you have for each question? Like were there a lot of shorter questions or was it just a few questions that took a while? For me, I ended the midterms with a lot of time since a decent amount of questions were conceptual...
by Allan Nguyen 2G
Thu Jan 14, 2021 11:40 pm
Forum: Administrative Questions and Class Announcements
Topic: More Audio Visual Focus Topics
Replies: 8
Views: 46

Re: More Audio Visual Focus Topics

For last quarter, he only had it for the fundamentals and quantum. I'm assuming it'll be the same and there will be no addition of the audio visual focus topics.
by Allan Nguyen 2G
Wed Jan 13, 2021 10:02 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: pH and pKa
Replies: 6
Views: 30

pH and pKa

I know that they're both different, but how can I differentiate between the two in terms of application and concepts?
by Allan Nguyen 2G
Wed Jan 13, 2021 5:59 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Left vs. Right
Replies: 29
Views: 127

Re: Left vs. Right

They're the same and the terms are used when you look at the K value to determine whether reactants or products are favored in a reaction.
by Allan Nguyen 2G
Fri Jan 08, 2021 9:24 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Sapling Wk 1 Q2
Replies: 3
Views: 86

Sapling Wk 1 Q2

Hello, I've been having trouble trying to work this problem. I don't know if I'm doing it right but I multiplied the given equilibrium moles of O2 by 2 to get 0.240 mol for SO2. I then added the equilibrium moles of SO2 and O2 to get 0.360, which I then subtracted from the 0.820 initial moles of SO3...
by Allan Nguyen 2G
Fri Jan 08, 2021 7:28 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Q and K
Replies: 46
Views: 191

Re: Q and K

You can calculate Q to figure out where the reaction will proceed if given the equilibrium constant, K. Similar to what Silvi said, when Q<K the reaction will proceed to the right and vice versa when Q>K the reaction will proceed to the left.
by Allan Nguyen 2G
Fri Jan 08, 2021 5:20 pm
Forum: Administrative Questions and Class Announcements
Topic: Audio-Visual Topics
Replies: 13
Views: 84

Re: Audio-Visual Topics

I think it's just for equilibrium, since for 14A the audio-visual topics were only for the fundamentals review and early quantum.
by Allan Nguyen 2G
Thu Jan 07, 2021 9:05 pm
Forum: Administrative Questions and Class Announcements
Topic: Sapling Assignments
Replies: 28
Views: 154

Re: Sapling Assignments

They're optional but I found them to be helpful for Chem 14A last quarter in terms of review and getting used to Sapling.
by Allan Nguyen 2G
Wed Jan 06, 2021 12:57 pm
Forum: Student Social/Study Group
Topic: Advice for someone who didn't take 14A with professor Lavelle
Replies: 61
Views: 338

Re: Advice for someone who didn't take 14A with professor Lavelle

Like everyone else has replied to on this post, I highly recommend the UA workshops because they expose you do different types of problems that are very similar to questions on midterms and final exams.
by Allan Nguyen 2G
Mon Jan 04, 2021 9:55 pm
Forum: Administrative Questions and Class Announcements
Topic: Chemistry Posts in 14B
Replies: 155
Views: 2313

Re: Chemistry Posts in 14B

I think we keep our accounts but if you have a new discussion section for 14B, change your username under "Register Alias and Password" when logged in.
by Allan Nguyen 2G
Thu Dec 10, 2020 1:39 pm
Forum: Bronsted Acids & Bases
Topic: How do we know if its an acid or base?
Replies: 3
Views: 44

Re: How do we know if its an acid or base?

Going off of what Samantha said, it really depends on the context of the problem whether the compound is being used as an acid or base. Molecules that can act as both as an acid or base is considered amphiprotic. For example, HCO3- can become CO3^2- or H2CO3. Edit: Sorry I didn't mean to say amphote...
by Allan Nguyen 2G
Wed Dec 09, 2020 9:43 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: lone pairs and 180 degrees
Replies: 4
Views: 52

Re: lone pairs and 180 degrees

While I can't really explain why linear molecules can have lone pairs, I know for a fact that linear molecules can have three or four lone pairs. I put an attachment for the VSEPR geometries and in the bottom right there are two linear VSEPR geometries with three or four lone pairs. I think it's bec...
by Allan Nguyen 2G
Wed Dec 09, 2020 9:38 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: Bonding sites
Replies: 2
Views: 24

Re: Bonding sites

For hydrogen bonding, we know that a hydrogen bond can only occur between an H atom and a F, O, or N atom. When looking at thymine, we need to look at the amount of hydrogen atoms and the amount of lone pairs in any atom that is F, O, or N. In the thymine molecule, there's two hydrogen atoms, so tha...
by Allan Nguyen 2G
Wed Dec 09, 2020 9:16 pm
Forum: Administrative Questions and Class Announcements
Topic: Do we need to memorize all 15 shapes
Replies: 5
Views: 56

Re: Do we need to memorize all 15 shapes

I think you should memorize all of them but I remember one of the UAs saying that there are some shapes such as T-shape being pretty rare to occur in problems. The ones I put an emphasis on were bent, linear, tetrahedral, trigonal planar, and trigonal pyramidal but yeah I'd still try and memorize al...
by Allan Nguyen 2G
Wed Dec 09, 2020 5:01 pm
Forum: Naming
Topic: Aqua vs Hydrate
Replies: 12
Views: 110

Re: Aqua vs Hydrate

Yes I think I saw in another chemistry community post that when H2O is within the coordination compound, it's name is aqua. For example, in the coordination compound [CrCl3(NH3)2(OH2)]+ , H2O would be referred to as aqua. When outside of the bracket, H2O is referred to as hydrate. Honestly, I'm not ...
by Allan Nguyen 2G
Mon Dec 07, 2020 10:48 pm
Forum: Identifying Acidic & Basic Salts
Topic: Sapling Wk 10 Q7
Replies: 2
Views: 44

Sapling Wk 10 Q7

Hello, I'm having trouble classifying whether a salt is acidic, basic, or neutral. Can someone explain to me how to determine what these salts are? Thanks in advance!
by Allan Nguyen 2G
Fri Dec 04, 2020 10:36 pm
Forum: Ionic & Covalent Bonds
Topic: Polar and Nonpolar
Replies: 28
Views: 196

Re: Polar and Nonpolar

Don't forget that a molecule can have polar bonds but can still be a nonpolar molecule due to its shape.
by Allan Nguyen 2G
Fri Dec 04, 2020 5:08 pm
Forum: Student Social/Study Group
Topic: How are you?
Replies: 117
Views: 876

Re: How are you?

Super anxious but studying and doing more practice problems makes me feel more ready for the upcoming final :)
by Allan Nguyen 2G
Fri Dec 04, 2020 12:10 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: List of Ligands
Replies: 5
Views: 18

Re: List of Ligands

There's a list of ligands on Dr. Lavelle's Chem 14A site titled "Naming Coordination Compounds." I'm just going to assume he wants us to memorize those since they're on his site.
by Allan Nguyen 2G
Thu Dec 03, 2020 7:01 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Weak/strong acids/bases
Replies: 2
Views: 16

Re: Weak/strong acids/bases

Adding onto what the post above said, an example of this could be the strong acid HCl and the weak acid HF. We can tell that HCl is a strong acid because it's bond between H and Cl is weak. Since the Cl atom has a larger atomic radius this creates a longer bond length resulting in a weak bond. The w...
by Allan Nguyen 2G
Thu Dec 03, 2020 3:08 am
Forum: Naming
Topic: Ligands
Replies: 3
Views: 22

Re: Ligands

There is a pdf on Lavelle's Chem 14A website titled "Naming Coordination Compounds." I was told that these are the main ones that Lavelle wants us to memorize.
by Allan Nguyen 2G
Tue Dec 01, 2020 4:20 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8776
Views: 1490998

Re: Post All Chemistry Jokes Here

A photon checks into a hotel and the bellboy asks, "Can I take your bags?" The photon answers, "No thanks, I'm travelling light."
by Allan Nguyen 2G
Wed Nov 25, 2020 9:39 pm
Forum: Hybridization
Topic: Clarification on 11/23 Monday's Lecture
Replies: 5
Views: 35

Re: Clarification on 11/23 Monday's Lecture

I think it is too because I can't see any way you'd get sp3 for the hybridization of ethylene, only sp2.
by Allan Nguyen 2G
Wed Nov 25, 2020 9:36 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Sapling Question #12
Replies: 2
Views: 24

Re: Sapling Question #12

That's really odd, I have the same exact lewis structure as you and it says that it's correct. Did you get sp^3 for the hybridization of the carbon and oxygen atoms and say that it was polar?
by Allan Nguyen 2G
Tue Nov 24, 2020 9:50 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR Simulation
Replies: 2
Views: 38

VSEPR Simulation

Hello, I just wanted to link this here since I found this simulation to be very helpful for me when visualizing VSEPR shapes. Just wanted to link this out there to anyone else having trouble visualizing VSEPR shapes.
https://phet.colorado.edu/sims/html/mol ... es_en.html
by Allan Nguyen 2G
Mon Nov 23, 2020 5:33 pm
Forum: DeBroglie Equation
Topic: De broglie equation versus E=hv
Replies: 9
Views: 139

Re: De broglie equation versus E=hv

I believe the De broglie equation is used when determining whether the object being evaluated has wavelike properties or not. For example, if you're given the energy of an object that is not light, you can use the E=hv equation to find the velocity and use that velocity to plug into the De broglie e...
by Allan Nguyen 2G
Mon Nov 23, 2020 5:20 pm
Forum: Administrative Questions and Class Announcements
Topic: UA Sessions for Thanksgiving
Replies: 1
Views: 26

UA Sessions for Thanksgiving

I was just wondering, will there still be UA sessions for this week?
by Allan Nguyen 2G
Sat Nov 21, 2020 4:46 pm
Forum: Student Social/Study Group
Topic: Study Tips for Final Exam
Replies: 57
Views: 451

Re: Study Tips for Final Exam

The textbooks questions and readings have helped me a lot in understanding how to do calculation based problems along with conceptual based problems. Also, the workshops that happen every week are so helpful, they expose you to different types of questions and have help me a lot on the midterms.
by Allan Nguyen 2G
Sat Nov 21, 2020 4:43 pm
Forum: Ionic & Covalent Bonds
Topic: Covalent Character
Replies: 14
Views: 93

Re: Covalent Character

I remember there was like a scale to determine covalent or ionic character where if the electronegativity difference is greater than 1.5 its more ionic and if less an 1.5 its more covalent.
by Allan Nguyen 2G
Mon Nov 16, 2020 6:36 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Counting Valence Electrons D Orbital Vs S and P Orbitals
Replies: 3
Views: 26

Re: Counting Valence Electrons D Orbital Vs S and P Orbitals

When we look at the periodic table, we know that 5s and 5p subshells are of a higher energy level than 4d. The electron configuration for Sb is [Kr]4d^10 5s^2 5p^3. We know that valence electrons are the outermost electrons of an atom, so when we look at this electron configuration, the 5 electrons ...
by Allan Nguyen 2G
Mon Nov 16, 2020 6:01 pm
Forum: Bond Lengths & Energies
Topic: Boiling Point of Molecules
Replies: 2
Views: 31

Boiling Point of Molecules

Hello, I was going over the worksheet from Riya Shah's workshop today and one of the questions asks to put Br2, Cl2, and I2 from lowest to highest BP. Since these molecules only have LDFs, the molecule with more electrons and larger molar mass form stronger LDFs in which the answer was Cl2<Br2<I2. H...
by Allan Nguyen 2G
Mon Nov 16, 2020 1:31 am
Forum: Resonance Structures
Topic: Textbook 2C.17
Replies: 2
Views: 38

Textbook 2C.17

Hello, I was wondering how do you figure out which resonance structure makes the most dominant contribution to a resonance hybrid? Thanks in advance!
by Allan Nguyen 2G
Fri Nov 13, 2020 7:58 pm
Forum: Administrative Questions and Class Announcements
Topic: Midtern #2
Replies: 6
Views: 40

Re: Midtern #2

We use the same sheets we used on the last midterm which was the equations and constants sheet along with a periodic table.
by Allan Nguyen 2G
Thu Nov 12, 2020 8:32 pm
Forum: Dipole Moments
Topic: induced dipole vs dipole
Replies: 11
Views: 47

Re: induced dipole vs dipole

I believe induced dipole-induced dipole bonds occurs among all atoms and molecules. This occurs when the molecule temporarily distorts another neighboring molecule causing a temporary attraction causing the induced dipole-induced dipole bond. Dipole-dipole interactions can only occur between two pol...
by Allan Nguyen 2G
Wed Nov 11, 2020 7:50 pm
Forum: Dipole Moments
Topic: Dipole dipole vs LDF
Replies: 10
Views: 67

Re: Dipole dipole vs LDF

Dipole dipole and LDFs are both intermolecular forces. LDFs occur between every atom and molecule in intermolecular forces, while dipole dipole only occurs between polar molecules that are dipole.
by Allan Nguyen 2G
Tue Nov 10, 2020 5:53 pm
Forum: Student Social/Study Group
Topic: Test Anxiety
Replies: 62
Views: 357

Re: Test Anxiety

I find taking deep breathes really helps. Also, whenever I find myself taking too much time on a problem I just move on the next problem and go back to it later. What helped me the most is just doing practice problems, so when it came to the test I knew what to do immediately.
by Allan Nguyen 2G
Mon Nov 09, 2020 4:56 pm
Forum: Student Social/Study Group
Topic: Mid-quarter Check in
Replies: 67
Views: 294

Re: Mid-quarter Check in

The quarter system has been going pretty fast but I've been managing my time pretty well and am able to keep up. I'm beginning to feel burnt out with all these midterms and work going around but we're already halfway there.
by Allan Nguyen 2G
Thu Nov 05, 2020 7:45 pm
Forum: Lewis Structures
Topic: Sapling Lewis Strucutres
Replies: 5
Views: 45

Re: Sapling Lewis Strucutres

I remember Lavelle saying that in nature wants to be stable. By looking at the overall formal charge of a molecule, the Lewis structure that would contribute the most I assume would be the most stable molecule.
by Allan Nguyen 2G
Wed Nov 04, 2020 11:39 pm
Forum: Lewis Structures
Topic: Sapling Week 5-6 Q4
Replies: 1
Views: 33

Sapling Week 5-6 Q4

Hello, can someone help me with this? I know that double bonds are shorter in pm than single bonds, but I'm fully understanding the problem as I keep getting it wrong. Thanks in advance!
by Allan Nguyen 2G
Wed Nov 04, 2020 11:22 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Representing Electron Configurations for P-orbitals
Replies: 6
Views: 44

Re: Representing Electron Configurations for P-orbitals

I believe the p^n format is less descriptive than the px, py, pz format. The latter format is more specific and helps display Hund's rule in which each orbital in the 2p subshell is occupied with one electron before any orbital has two electrons.
by Allan Nguyen 2G
Tue Nov 03, 2020 7:05 pm
Forum: Trends in The Periodic Table
Topic: Why is the ionization energy of O lower than N?
Replies: 13
Views: 113

Why is the ionization energy of O lower than N?

I remember hearing that ionization energy increases across a period. Why does oxygen have a lower ionization energy than nitrogen?
by Allan Nguyen 2G
Tue Nov 03, 2020 6:46 pm
Forum: Electronegativity
Topic: Periodic Table Trend
Replies: 37
Views: 395

Re: Periodic Table Trend

They both increase across a period and decrease down a group.
by Allan Nguyen 2G
Fri Oct 30, 2020 7:14 pm
Forum: DeBroglie Equation
Topic: Sapling Homework #14
Replies: 2
Views: 34

Re: Sapling Homework #14

For the second part of this problem, you want to use the de Broglie equation and rearrange it to find the velocity of the electron. So after rearranging the equation it should be v = h/m λ. Convert the wavelength to meters, and plug in the values and you should get 290.96 m.s^-1 for velocity. I woul...
by Allan Nguyen 2G
Thu Oct 29, 2020 3:49 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Atomic Spectra Post Module Question
Replies: 2
Views: 38

Re: Atomic Spectra Post Module Question

With the wavelength, you can look at the electromagnetic spectrum and compare your wavelength to the wavelengths that are on the spectrum. Here is an attachment, you can see that the visible light portion is around 380 nm to ~700 nm. I just memorized the general parts of the electromagnetic spectrum...
by Allan Nguyen 2G
Wed Oct 28, 2020 6:22 pm
Forum: DeBroglie Equation
Topic: sapling hw problem
Replies: 5
Views: 128

Re: sapling hw problem

For the second part of this problem, you want to use the de Broglie equation and rearrange it to find the velocity of the electron. So after rearranging the equation it should be v = h/m λ. Convert the wavelength to meters, and plug in the values and you should get 382.84 m.s^-1. I would then use th...
by Allan Nguyen 2G
Tue Oct 27, 2020 11:34 pm
Forum: Photoelectric Effect
Topic: Work function or incoming light
Replies: 6
Views: 52

Re: Work function or incoming light

When the problem asks to find the energy to remove an electron, that would be considered the work function or threshold energy. If a problem asks for the energy that causes the photoejection of an electron, that would be the incoming light or incident light.
by Allan Nguyen 2G
Mon Oct 26, 2020 6:37 pm
Forum: Student Social/Study Group
Topic: Midterm
Replies: 5
Views: 88

Re: Midterm

I think when Dr. Lavelle said up to 1D.2, he just meant the section to read up to for the 1D section. I don't think there are any problems you need to do because on the outline, he did not assign the problem 1D.2. I think he is just going to test us on concepts.
by Allan Nguyen 2G
Fri Oct 23, 2020 4:56 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Heisenberg Indeterminacy Q from Workshop
Replies: 1
Views: 33

Heisenberg Indeterminacy Q from Workshop

Hello, I was wondering if someone could help me with this. I was late to Kate Santoso's workshop last night. Thanks in advance! Q1A. The uncertainty in the momentum of a football thrown by Tom Brady during the superbowl traveling at 40 m/s is 1 x 10-6 of its momentum. What is its uncertainty in posi...
by Allan Nguyen 2G
Fri Oct 23, 2020 2:31 am
Forum: DeBroglie Equation
Topic: Sapling Hw 2 #19
Replies: 10
Views: 130

Re: Sapling Hw 2 #19

I would just make sure to check for unit conversions. Don't forget that the joule unit in Planck's constant for the De Broglie equation is 1 kg.m^2.s^-2 Does this mean that you do not input the value as 6.626*10^-34 J.s into the equation? My bad, I didn't mean to put the 1 before the kg.m^2.s^-2. Y...
by Allan Nguyen 2G
Fri Oct 23, 2020 12:13 am
Forum: General Science Questions
Topic: When to use sig figs
Replies: 19
Views: 114

Re: When to use sig figs

I believe that in the middle of calculations, you wouldn't round down values to sig figs. However, when calculating your final answer, you would then use sig figs because if you used sig figs in the middle of the problem and then used those values to calculate the solution, the answer would be less ...
by Allan Nguyen 2G
Thu Oct 22, 2020 11:44 pm
Forum: DeBroglie Equation
Topic: Sapling Hw 2 #19
Replies: 10
Views: 130

Re: Sapling Hw 2 #19

I would just make sure to check for unit conversions. Don't forget that the joule unit in Planck's constant for the De Broglie equation is 1 kg.m^2.s^-2
by Allan Nguyen 2G
Thu Oct 22, 2020 7:59 pm
Forum: Student Social/Study Group
Topic: Midterm study
Replies: 5
Views: 45

Re: Midterm study

I suggest just redoing practice problems from the textbook and post-assessment modules. Also, the workshops are also really helpful if you want extra practice.
by Allan Nguyen 2G
Mon Oct 19, 2020 7:29 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Saping HW Q.8
Replies: 8
Views: 77

Saping HW Q.8

I'm having trouble figuring out to get started with this problem. Thanks in advance! "A blue line is observed at 486.1 nm in the spectrum of atomic hydrogen. Determine the values of n for the beginning and ending energy levels of the electron during the emission of energy that leads to this spe...
by Allan Nguyen 2G
Sat Oct 17, 2020 5:57 pm
Forum: Student Social/Study Group
Topic: How are you studying?
Replies: 203
Views: 1384

Re: How are you studying?

I've just been taking notes from the lectures, and doing the textbook problems assigned for each unit. Something that really helps is attending the workshops, the UAs explain everything so well and the worksheets help out so much.
by Allan Nguyen 2G
Fri Oct 16, 2020 8:20 pm
Forum: Einstein Equation
Topic: E=hv
Replies: 8
Views: 102

Re: E=hv

Dr. Lavelle changed the negative sign in -4.09x10^-19 J to positive sign because I think he specifically stated that energy cannot be negative. The negative sign represented that the electrons energy decrease and was released as electromagnetic radiation. If you plug the -4.09x10^-19 and divide it b...
by Allan Nguyen 2G
Fri Oct 16, 2020 6:53 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Q.42 for Atomic Spectra Post Module
Replies: 4
Views: 83

Q.42 for Atomic Spectra Post Module

An excited hydrogen atom emits light with a frequency of 1.14 x 1014 Hz to reach the energy level n = 4. In what principle quantum level did the electron begin? Does anyone know how to do this with the E = -hR/n^2 equation or does it have to be the Rydberg equation? I just remember Dr. Lavelle sayin...
by Allan Nguyen 2G
Thu Oct 15, 2020 4:40 pm
Forum: Administrative Questions and Class Announcements
Topic: Week 2&3 Sapling Homework
Replies: 1
Views: 32

Re: Week 2&3 Sapling Homework

Yes, it's due midnight Sunday Week 3 (Oct. 25) since we will still be learning Quantum next week
by Allan Nguyen 2G
Tue Oct 13, 2020 6:08 pm
Forum: Photoelectric Effect
Topic: Photoelectric Effect Post-Module #28
Replies: 4
Views: 37

Re: Photoelectric Effect Post-Module #28

For Part A you use KE = 1/2 mv^2. The mass of an electron is approx 9.109*10^-31 kg. Therefore, by plugging in what's given into the formula, you should have (1/2)*(9.109*10^-31)(6.61*10^5)^2 which should result in the answer.
by Allan Nguyen 2G
Sat Oct 10, 2020 12:14 am
Forum: Molarity, Solutions, Dilutions
Topic: Question G.25 in Fundamentals
Replies: 2
Views: 37

Question G.25 in Fundamentals

Hello, can someone explain this problem to me? I am having trouble understanding the problem. I thought that mols of solute don't change in a dilution. G.25 Practitioners of the branch of alternative medicine known as homeopathy claim that very dilute solutions of substances can have an effect. Is t...
by Allan Nguyen 2G
Sat Oct 10, 2020 12:02 am
Forum: Balancing Chemical Reactions
Topic: WK 1 Sapling #10
Replies: 7
Views: 91

Re: WK 1 Sapling #10

I went to a workshop and someone asked this question, and the UA ended up saying that the molar mass should have been given because there would have been no way for us to find it.
by Allan Nguyen 2G
Thu Oct 08, 2020 12:49 am
Forum: Student Social/Study Group
Topic: Office Hours
Replies: 7
Views: 57

Re: Office Hours

It's fine, you could just drop into an office hours session and just listen. Sometimes other students will ask questions that you didn't know you even had.
by Allan Nguyen 2G
Wed Oct 07, 2020 11:32 pm
Forum: General Science Questions
Topic: Need help with finding kinetic energy, energy and frequency
Replies: 1
Views: 84

Need help with finding kinetic energy, energy and frequency

Light hits a sodium metal surface and the velocity of the ejected electron is 6.61 x 105 m.s-1. The work function for sodium is 150.6 kJ.mol-1. Answer the following three questions. A. What is the kinetic energy of the ejected electron? B. How much energy is required to remove an electron from one s...
by Allan Nguyen 2G
Tue Oct 06, 2020 1:59 pm
Forum: Administrative Questions and Class Announcements
Topic: Office Hours and other Sessions [ENDORSED]
Replies: 4
Views: 149

Office Hours and other Sessions [ENDORSED]

I was planning on attending the office hours and sessions that Dr. Lavelle offers, but sometimes I do not have any questions to ask. Is it fine if I just join the calls without any prior questions?
by Allan Nguyen 2G
Tue Oct 06, 2020 1:52 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8776
Views: 1490998

Re: Post All Chemistry Jokes Here

What kind of bear dissolves in water?

A polar bear

Go to advanced search