Search found 34 matches

by Kaiya_PT_1H
Sun Nov 29, 2020 9:40 pm
Forum: Dipole Moments
Topic: H-Bonds
Replies: 14
Views: 66

Re: H-Bonds

When a question asks about whether hydrogen bonding is possible with a certain molecule, do they mean hydrogen bonding to itself or hydrogen bonding with water?
by Kaiya_PT_1H
Sun Nov 29, 2020 9:39 pm
Forum: Sigma & Pi Bonds
Topic: Pi Bonds Being Parallel or Perpendicular
Replies: 2
Views: 16

Re: Pi Bonds Being Parallel or Perpendicular

that diagram was a super helpful visualization, thanks Valerie!
by Kaiya_PT_1H
Sun Nov 29, 2020 9:37 pm
Forum: Sigma & Pi Bonds
Topic: Sapling Question #16 about delocalized pi bond
Replies: 3
Views: 13

Re: Sapling Question #16 about delocalized pi bond

conceptually, the "delocalized" part refers to the fact that in a molecule represented with resonance structures, the electrons actually form multiple bonds that don't correspond to the bond lengths of double or triple bonds. They basically go between the different areas that they would be...
by Kaiya_PT_1H
Sun Nov 29, 2020 9:34 pm
Forum: Sigma & Pi Bonds
Topic: Delocalized pi bond
Replies: 7
Views: 25

Re: Delocalized pi bond

I'm not 100% sure if this is actually true, but I think any molecule that has resonance structures has at least one delocalized pi bond! since resonance structures result from different combinations of multiple bonds and pi bonds are only present in double or triple bonds, that's what makes sense to...
by Kaiya_PT_1H
Sun Nov 15, 2020 8:25 pm
Forum: Student Social/Study Group
Topic: Class grade
Replies: 18
Views: 95

Re: Class grade

Yes like Orla said, check with your major! I know in the spring a lot of majors allowed you to take classes P/NP even if it was a major requirement, but I don't think that's the case this quarter.
by Kaiya_PT_1H
Sun Nov 15, 2020 8:21 pm
Forum: Bond Lengths & Energies
Topic: Sapling #4
Replies: 4
Views: 30

Re: Sapling #4

Yep I basically did the same as Jasmine, it seems logical to rule out answers that include "overwhelming" because the observed bond lengths seemed not to be super close to either the single or double bond lengths, but somewhere in the middle.
by Kaiya_PT_1H
Sun Nov 15, 2020 8:14 pm
Forum: Electronegativity
Topic: polar vs nonpolar
Replies: 19
Views: 56

Re: polar vs nonpolar

Yes I agree with Shamaya, the lower limit for a polar covalent bond is 0.5. The upper limit is around 1.6 or 1.7, and if the electronegativity difference is more than 2 it's considered to be an ionic bond!
by Kaiya_PT_1H
Sun Nov 15, 2020 8:09 pm
Forum: Lewis Structures
Topic: Sapling Question #4
Replies: 5
Views: 30

Re: Sapling Question #4

I don't think triple bonds were being considered, but otherwise I agree with Kaihan! I think it's also logical to just rule out "overwhelmingly" since the observed bond lengths weren't clearly super close to a particular single or double bond length, if that makes sense.
by Kaiya_PT_1H
Sun Nov 15, 2020 8:03 pm
Forum: Administrative Questions and Class Announcements
Topic: Electronegativity chart for Midterm
Replies: 7
Views: 29

Re: Electronegativity chart for Midterm

Are there any other charts of trends that he mentioned? I guess all the information will be given to us but I'm just curious if I missed something.
by Kaiya_PT_1H
Sun Nov 08, 2020 9:12 pm
Forum: Administrative Questions and Class Announcements
Topic: Question for Students about High School Chem
Replies: 25
Views: 107

Re: Question for Students about High School Chem

I took AP chem 3 years ago and I remember having seen most of the topics so far, but I think Lavelle goes more in-depth with the explanations of why experiments were relevant and how they relate to the equations/concepts. Basically he gives more context for everything than we got in my AP chem class.
by Kaiya_PT_1H
Sun Nov 08, 2020 9:07 pm
Forum: Administrative Questions and Class Announcements
Topic: Chem 14BL?
Replies: 7
Views: 47

Re: Chem 14BL?

I've heard that it's easier if you take 14BL after 14B, but either way is possible. Personally, I'm hoping that in the spring they might offer some in-person labs for people in Westwood...
by Kaiya_PT_1H
Sun Nov 08, 2020 9:05 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm 2 Question Count
Replies: 17
Views: 96

Re: Midterm 2 Question Count

Are we doing respondus and zoom proctoring again? My TA said he thought that the easiest thing would be to have Respondus on your laptop and Zoom on another device (probably your phone) since some people had trouble getting into the Zoom call once they were in the lockdown browser. But he did say t...
by Kaiya_PT_1H
Sun Nov 08, 2020 9:03 pm
Forum: Bond Lengths & Energies
Topic: Bond length
Replies: 11
Views: 39

Re: Bond length

I think for the post above, if you're using > to indicate one length is greater than another length, it would actually be single > double > triple since triple bonds are the shortest.
by Kaiya_PT_1H
Sun Nov 08, 2020 8:59 pm
Forum: Lewis Structures
Topic: structure of (CO3)2-
Replies: 4
Views: 23

Re: structure of (CO3)2-

You can also do what Lavelle did last week in setting up a Lewis structure diagram by adding up all the valence electrons and the overall charge. In this case, carbon would have 4 valence electrons, each oxygen should have 6, and there should be two extra to result in the overall 2- charge. Therefor...
by Kaiya_PT_1H
Sun Nov 01, 2020 4:14 pm
Forum: Student Social/Study Group
Topic: Test Scored for Midterm 1
Replies: 49
Views: 345

Re: Test Scored for Midterm 1

Will we be able to go over the midterms to see what questions we got wrong and what the correct answers were?
by Kaiya_PT_1H
Sun Nov 01, 2020 10:22 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Orbital vs. Subshell
Replies: 13
Views: 67

Re: Orbital vs. Subshell

What is the difference between a shell and a sub-shell? And which is the orbital within? As Megan said above, shells include electrons with the same principal quantum number (n). I believe this could also be called the energy level. subshells are the different configurations within the shell, which...
by Kaiya_PT_1H
Sun Nov 01, 2020 10:01 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Ground State Electron Configuration
Replies: 4
Views: 27

Re: Ground State Electron Configuration

I agree with what everyone said above, but also check to make sure it's not one of the two exceptions he talked about! The excited states of chromium and copper might look like what you would expect the ground state to look like (with the 4s orbital filled).
by Kaiya_PT_1H
Wed Oct 28, 2020 7:11 pm
Forum: Properties of Light
Topic: Do we need to know the ranges of waves on the electromagnetic spectrum?
Replies: 7
Views: 54

Do we need to know the ranges of waves on the electromagnetic spectrum?

I noticed that there are a lot of textbook questions asking you to identify where a certain frequency or wavelength would fall on the electromagnetic spectrum (like whether it's UV, visible light, infrared, etc.). Is that something we need to memorize for the midterm?
by Kaiya_PT_1H
Wed Oct 28, 2020 6:57 pm
Forum: Properties of Light
Topic: 1A.9 problem
Replies: 7
Views: 69

Re: 1A.9 problem

okay cool, glad it's not just me! I think based on the range for microwaves it would make sense anyway, as Silvi said.
by Kaiya_PT_1H
Wed Oct 28, 2020 5:01 pm
Forum: Properties of Light
Topic: 1A.9 problem
Replies: 7
Views: 69

Re: 1A.9 problem

Does anyone else get an answer of the wavelength being 1 m? In the back of the book it says the answer is 1 nm but I don't see how I'm getting it wrong somehow.
by Kaiya_PT_1H
Sun Oct 25, 2020 10:27 pm
Forum: Empirical & Molecular Formulas
Topic: Periodic Table and Calculations
Replies: 19
Views: 103

Re: Periodic Table and Calculations

Concerning calculators, you can use a variety of different ones. I personally use TI-84 CE calculator, but desmos also has a scientific calculator you can use. On Dr. Lavelle's website, he has a periodic table that you can use. Don't plan to use desmos on the test though! the respondus browser won'...
by Kaiya_PT_1H
Sun Oct 25, 2020 10:16 pm
Forum: SI Units, Unit Conversions
Topic: Do I need to do very single textbook question on the syllabus?
Replies: 34
Views: 193

Re: Do I need to do very single textbook question on the syllabus?

Hey I kind of have a similar question, but couldn't figure out how to make a new post. Does anyone know if there are answers to the questions in the textbook to check if we are doing them correctly? Yes, the end of the book has an "odd-numbered exercises" section where it lists all the an...
by Kaiya_PT_1H
Sun Oct 25, 2020 10:13 pm
Forum: Molarity, Solutions, Dilutions
Topic: Solute vs Solvent
Replies: 5
Views: 48

Re: Solute vs Solvent

I think most of these problems have one solid component and one liquid component, so I would think the easiest way to figure out the solute/solvent in most problems would be to assume the solid being dissolved is the solute and the liquid it's being dissolved in is the solvent.
by Kaiya_PT_1H
Sun Oct 25, 2020 10:08 pm
Forum: Molarity, Solutions, Dilutions
Topic: Stuck on Sapling HW
Replies: 11
Views: 125

Re: Stuck on Sapling HW

Why do we need to convert from g to moles here? Does the molarity equation need to have the compound in moles instead of grams? I just don't know the reasoning for needing moles. Thanks. We have to convert from grams to moles because the unit for molarity is moles per liter. The equation M = n/V us...
by Kaiya_PT_1H
Sat Oct 17, 2020 9:55 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Molar Mass and Molecular Mass Difference?
Replies: 19
Views: 177

Re: Molar Mass and Molecular Mass Difference?

joshtully wrote:What is an amu? I understand that it is a unit for molecular mass, but what does it stand for?


amu means "atomic mass unit" which is a measurement based on the carbon atom: 1 amu = 1/12 the mass of an unbound carbon atom. https://www.thoughtco.com/definition-of ... amu-604366
by Kaiya_PT_1H
Sat Oct 17, 2020 9:50 pm
Forum: Significant Figures
Topic: Sapling HW #4
Replies: 31
Views: 244

Re: Sapling HW #4

I don't understand why a trailing zero isn't a significant figure. If 950000 is different from 950001, then shouldn't all the digits be significant figures? Perhaps I misunderstand the purpose of significant figures. 950000 only has 2 significant figures because it's only precise up to the ten thou...
by Kaiya_PT_1H
Sat Oct 17, 2020 9:41 pm
Forum: Electronegativity
Topic: Hydrogen
Replies: 6
Views: 168

Re: Hydrogen

Nan_Guan_3J wrote:I think it's because H only has 2 protons. and also, Hydrogen is not a very typical atom. although it's placed in the upper right corner on the periodic table, it doesn't follow some of the trends that apply to most other atoms.


Hydrogen actually has one proton, helium has 2 protons!
by Kaiya_PT_1H
Sat Oct 17, 2020 9:16 pm
Forum: Quantum Numbers and The H-Atom
Topic: Lymer and Balmer series
Replies: 5
Views: 48

Re: Lymer and Balmer series

He also said in the lecture that the Lyman series emits waves in the ultraviolet range and the Balmer series emits waves in the visible light range. I'm not sure how relevant that is though.
by Kaiya_PT_1H
Sat Oct 17, 2020 8:55 pm
Forum: Properties of Light
Topic: Frequency vs Wavelength
Replies: 22
Views: 134

Re: Frequency vs Wavelength

I noticed in a previous lecture when prof was going over the equations like E=hv or c=λv the letter "v" was written with a bit of a curve. Is this intentional so we know that this V is referring to frequency and not velocity as it would in other equations, or is that just prof's handwriti...
by Kaiya_PT_1H
Thu Oct 08, 2020 12:29 pm
Forum: Student Social/Study Group
Topic: STEM clubs
Replies: 8
Views: 90

STEM clubs

Anyone have recommendations for STEM clubs to join that are active this fall? I know there are a lot of premed clubs, but I'd like to learn about more social-oriented clubs as well.
by Kaiya_PT_1H
Thu Oct 08, 2020 12:26 pm
Forum: Student Social/Study Group
Topic: Chemistry News
Replies: 76
Views: 50026

Re: Chemistry News

https://www.nytimes.com/2020/10/07/science/nobel-prize-chemistry-crispr.html https://www.cnn.com/2020/10/07/health/nobel-prize-2020-winner-chemistry-scn-intl/index.html For the first time in history, two women won the Nobel Prize in Chemistry (and didn't share it with a man)! They won the prize for ...
by Kaiya_PT_1H
Thu Oct 08, 2020 12:22 pm
Forum: Significant Figures
Topic: Significant Figures for Calculations with Molar Masses
Replies: 5
Views: 91

Re: Significant Figures for Calculations with Molar Masses

To add on to the previous replies, molar masses could also be adjusted to the level of accuracy that you need so that they don't interfere with calculations. If the source that you are using doesn't have the correct number of significant figures, and you think that it is a significant issue, you co...
by Kaiya_PT_1H
Thu Oct 08, 2020 12:19 pm
Forum: Significant Figures
Topic: Significant Figures In A Given Weight
Replies: 11
Views: 175

Re: Significant Figures In A Given Weight

For that question I believe that since 7 is an integer, there is no specific amount of significant figures that you should use. I would suggest using only 1 anyway since there are no zeros after the integer, just to be safe. Usually for questions involving moles and grams, you should use the least ...
by Kaiya_PT_1H
Thu Oct 08, 2020 12:07 pm
Forum: Ionic & Covalent Bonds
Topic: Is ionic or covalent stronger?
Replies: 31
Views: 340

Re: Is ionic or covalent stronger?

Last year in LS 7A, Dr. Maloy said that generally in life science, covalent bonds are considered to be stronger because chemical reactions occur almost entirely in aqueous solutions (the molecules with ionic bonds would be separated into ions). However I think in terms of just heating up a substance...

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