Search found 62 matches

by Katie Le 3K
Sun Jan 17, 2021 10:34 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Total Pressure
Replies: 16
Views: 30

Re: Total Pressure

Total pressures is the sum of all partial pressures in rxn.
by Katie Le 3K
Sun Jan 17, 2021 10:34 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: When would K be unchanged?
Replies: 26
Views: 49

Re: When would K be unchanged?

A better way to remember is that K changes w/ temperature.
by Katie Le 3K
Fri Jan 15, 2021 3:41 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: What is autoprotolysis? lavelle's lecture 1/15 [ENDORSED]
Replies: 7
Views: 50

What is autoprotolysis? lavelle's lecture 1/15 [ENDORSED]

In today's lecture, Dr. Lavelle says that if [H3O+] < 10^-7 its neutral because of autoprotolysis.

what is autoprotolysis
by Katie Le 3K
Fri Jan 15, 2021 3:37 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: the different Ks
Replies: 7
Views: 31

Re: the different Ks

They are all K constants meaning they calculate the same thing (equilibrium constant)
the subscripts denote the type of equilibrium constant it calculates.
Ka, Kb, Kw, Kc, and Kp are K of acid, base, dissociation constant of water, concentration, and partial pressure respectively.
by Katie Le 3K
Wed Jan 13, 2021 6:03 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Temperature
Replies: 36
Views: 87

Re: Temperature

Based on if the rxn is endo or exothermic, we can use temperature to find which side the rxn favors
by Katie Le 3K
Thu Jan 07, 2021 6:08 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Calculating Kc
Replies: 4
Views: 36

Re: Calculating Kc

You use the ICE chart. If you click feedback, Sapling should provide one for you.
by Katie Le 3K
Thu Jan 07, 2021 6:07 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Including H2O
Replies: 7
Views: 27

Re: Including H2O

H2O in liquid form is not included along w/ solids.
by Katie Le 3K
Thu Jan 07, 2021 6:06 pm
Forum: Ideal Gases
Topic: Kc for Gases
Replies: 11
Views: 70

Re: Kc for Gases

You would normally be given the concentrations or pressures. If you are given concentrations, its Kc. If you are given partial pressures, its Kp
by Katie Le 3K
Tue Jan 05, 2021 8:32 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Kc favoring products
Replies: 10
Views: 73

Re: Kc favoring products

Yes. It only slightly favors it. you cannot make a strong statement about the favor unless its greater than 10^3
by Katie Le 3K
Tue Jan 05, 2021 8:31 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Kc vs Kp
Replies: 14
Views: 69

Re: Kc vs Kp

Both are calculated the same way. Kc uses concentration Kp uses pressure.
by Katie Le 3K
Sat Dec 12, 2020 6:59 pm
Forum: Administrative Questions and Class Announcements
Topic: Final Content
Replies: 18
Views: 162

Re: Final Content

Cumulative w focus on topics we spend longer time on.
by Katie Le 3K
Fri Dec 04, 2020 3:00 am
Forum: Molarity, Solutions, Dilutions
Topic: What does mmol stand for?
Replies: 33
Views: 329

Re: What does mmol stand for?

1 mmole = .001 mole
by Katie Le 3K
Wed Dec 02, 2020 6:57 pm
Forum: General Science Questions
Topic: midterm 2 answers
Replies: 26
Views: 276

Re: midterm 2 answers

some ta's review it in office hours or you have to email them to set up a specific appointment
by Katie Le 3K
Wed Dec 02, 2020 6:55 pm
Forum: Student Social/Study Group
Topic: Final Exam Study Tips
Replies: 48
Views: 242

Re: Final Exam Study Tips

Read the textbook and do the problems assigned in the outlines. ALso, going to the UA sessions are really really helpful. I feel like they explain concepts really well
by Katie Le 3K
Wed Dec 02, 2020 6:52 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: oxidation number with outside bracket charge
Replies: 4
Views: 33

Re: oxidation number with outside bracket charge

The charge outside the bracket (2-) represents the overall charge of the molecule. Thus, the charges of the atoms inside the brackets should total up to 2-
by Katie Le 3K
Wed Dec 02, 2020 3:30 pm
Forum: Administrative Questions and Class Announcements
Topic: Will the final have partial credit?
Replies: 1
Views: 28

Will the final have partial credit?

will the final have partial credit like midterm 1?
by Katie Le 3K
Tue Dec 01, 2020 8:45 pm
Forum: Naming
Topic: Lecture Example [Co(Nh3)5 Cl]Cl2H2O
Replies: 8
Views: 52

Lecture Example [Co(Nh3)5 Cl]Cl2H2O

In lecture he called this pentaammine - chloro - cobalt (II) chloride dihydrate

I'm confused on the chloride and dihydrate outside of the ligand brackets.

Why is Cl chloride and not chloro and why is 2h2o dihydrate instead of diaqua?
by Katie Le 3K
Mon Nov 30, 2020 10:02 pm
Forum: Administrative Questions and Class Announcements
Topic: Step Up/UA Sessions
Replies: 10
Views: 110

Re: Step Up/UA Sessions

I like them a lot. I feel like I solidify my understanding of the Lavelle's lecture and you can ask them questions. They also give you practice problems that are very helpful imo. Highly rec going to Hannah's or Justin's sessions.
by Katie Le 3K
Mon Nov 30, 2020 10:00 pm
Forum: Administrative Questions and Class Announcements
Topic: Final exam (fall 2020 quarter)
Replies: 20
Views: 226

Re: Final exam (fall 2020 quarter)

Its everything we have learned (cumulative)
by Katie Le 3K
Mon Nov 30, 2020 9:59 pm
Forum: Administrative Questions and Class Announcements
Topic: PeppermintMocha
Replies: 11
Views: 266

Re: PeppermintMocha

Thank you so much!
by Katie Le 3K
Tue Nov 24, 2020 6:26 pm
Forum: Administrative Questions and Class Announcements
Topic: Chem 14B
Replies: 9
Views: 91

Re: Chem 14B

there shouldnt be any time conflicts with chem14b lecture
by Katie Le 3K
Tue Nov 24, 2020 1:22 am
Forum: Limiting Reactant Calculations
Topic: Combustion
Replies: 10
Views: 113

Re: Combustion

O2 is in excess for combustion problems. i think its just something we assume unless explicitly stated otherwise
by Katie Le 3K
Tue Nov 24, 2020 1:20 am
Forum: DeBroglie Equation
Topic: De broglie equation versus E=hv
Replies: 9
Views: 110

Re: De broglie equation versus E=hv

In terms of application, de broglie can be used on any object as it has mass as a variable. Whereas e=hv is for energy of a photon.
by Katie Le 3K
Tue Nov 24, 2020 1:18 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: isoelectronic
Replies: 12
Views: 82

Re: isoelectronic

Isoelectronic means that two things have the same amount of electrons. An example would be that Ag 3+ and Mg 2+ are isoelectronic.
by Katie Le 3K
Tue Nov 24, 2020 1:15 am
Forum: Administrative Questions and Class Announcements
Topic: Final Exam Date
Replies: 21
Views: 219

Re: Final Exam Date

Yea, i think its the myucla date because our final is going to be longer than our midterms so i dont think it'll fit into our 50 min discussion sessions
by Katie Le 3K
Tue Nov 24, 2020 1:13 am
Forum: Student Social/Study Group
Topic: Exercising Our Minds and Bodies
Replies: 103
Views: 503

Re: Exercising Our Minds and Bodies

i do some low impact hiit workouts from youtube when im watching tv. paula b has some really good ones. they're not too hard but it helps when you've been sitting at your desk the whole day :)))
by Katie Le 3K
Sun Nov 22, 2020 8:57 pm
Forum: Student Social/Study Group
Topic: How to relax after midterms
Replies: 54
Views: 258

Re: How to relax after midterms

i watch youtube or play video games :)))
by Katie Le 3K
Fri Nov 20, 2020 8:23 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Lewis acids and bases
Replies: 22
Views: 107

Re: Lewis acids and bases

A helpful way is it draw out the lewis structures of the molecules and see which one has lone pair electrons. The one with lone pair electrons is the Lewis base.
by Katie Le 3K
Sun Nov 15, 2020 11:14 pm
Forum: Resonance Structures
Topic: Resonance Structures Clarification
Replies: 8
Views: 48

Re: Resonance Structures Clarification

To know which one gives the most contribution, you have to look at the formal charges. the lewis structures with atoms whose formal charge is 0 or close to 0 are the most contributing
by Katie Le 3K
Thu Nov 12, 2020 2:52 am
Forum: Lewis Structures
Topic: Double Bonds
Replies: 11
Views: 85

Re: Double Bonds

You'd look to see if the formal charge of the molecule would be 0 because it's more stable/more likely to happen.
by Katie Le 3K
Thu Nov 12, 2020 2:51 am
Forum: Lewis Structures
Topic: Radicals
Replies: 12
Views: 38

Re: Radicals

Its basically just an unpaired electron so it'd look like a dot next to the element.
by Katie Le 3K
Thu Nov 12, 2020 2:50 am
Forum: Lewis Structures
Topic: Formal Charge
Replies: 5
Views: 37

Re: Formal Charge

It's like an extra step to verify you drew it correctly. Like if it was Na-, if your total charge ended up being -1 that'd be good.
by Katie Le 3K
Thu Nov 12, 2020 2:50 am
Forum: Lewis Structures
Topic: NHF2
Replies: 7
Views: 24

Re: NHF2

no! you should be able to determine the difference in electronegativity between them though.
by Katie Le 3K
Thu Nov 12, 2020 2:49 am
Forum: Lewis Structures
Topic: Lewis Acids and Bases
Replies: 2
Views: 41

Re: Lewis Acids and Bases

Hi, a lewis acid will accepts electrons while a lewis base will donates these electrons. the way i figure out is making lewis structures for the two molecules and comparing which one would be receiving an electron and which one gives an electron. as a general tip, molecules with +1,+2,+3, or any + m...
by Katie Le 3K
Mon Nov 09, 2020 12:13 am
Forum: Lewis Structures
Topic: lewis structure
Replies: 17
Views: 49

Re: lewis structure

The negative and positive refers to the charge. You can find it out by finding the formal charge of each element and just adding them all together.
by Katie Le 3K
Mon Nov 09, 2020 12:11 am
Forum: Student Social/Study Group
Topic: Post Midterm Blues
Replies: 71
Views: 606

Re: Post Midterm Blues

I also feel that way for some of my midterms but I think we can make it up during the next two finals!!!
by Katie Le 3K
Mon Nov 09, 2020 12:10 am
Forum: Calculating the pH of Salt Solutions
Topic: Is pH normally taken at equilibrium concentrations?
Replies: 7
Views: 241

Re: Is pH normally taken at equilibrium concentrations?

I think if not asked for it directly in the question, it's safe to assume its at equilibrium.
by Katie Le 3K
Mon Nov 09, 2020 12:09 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: What are orbitals?
Replies: 10
Views: 112

Re: What are orbitals?

Orbitals are math functions that describe the position of an electron using the quantum numbers.
by Katie Le 3K
Mon Nov 09, 2020 12:07 am
Forum: Resonance Structures
Topic: Valence Electrons [ENDORSED]
Replies: 43
Views: 255

Re: Valence Electrons [ENDORSED]

Yea the group number corresponds with the number of valence electrons.
by Katie Le 3K
Wed Nov 04, 2020 10:10 pm
Forum: Lewis Structures
Topic: Lewis structure for formaldehyde
Replies: 4
Views: 42

Lewis structure for formaldehyde

How come the hydrogen in CH20 doesn't have 8 filled valence electrons like C and O
by Katie Le 3K
Tue Nov 03, 2020 9:30 pm
Forum: Lewis Structures
Topic: How to find valence electrons of an element
Replies: 6
Views: 51

How to find valence electrons of an element

sorry if this is dumb but in Prof Lavelle's lecture, he was drawing a picture of the Lewis structure of Cl and said " we know that cl has 7 valence electrons" and then drew dots. but like how do i find out the valence electrons of cl? am i supposed to memorize it?
by Katie Le 3K
Tue Nov 03, 2020 6:21 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Why is the 4s state filled before the 3d state?
Replies: 14
Views: 122

Re: Why is the 4s state filled before the 3d state?

The 4s shell has less energy than 3d so electrons fill the lesser energy shell first.
by Katie Le 3K
Tue Nov 03, 2020 6:19 pm
Forum: DeBroglie Equation
Topic: De Broglie wavelength vs. wavelength
Replies: 7
Views: 78

Re: De Broglie wavelength vs. wavelength

De broglie wavelength is used when you have a mass and velocity. Whereas the other wavlength equations deal w frequency.
by Katie Le 3K
Mon Nov 02, 2020 12:09 am
Forum: Properties of Light
Topic: Wavelenght
Replies: 17
Views: 110

Re: Wavelenght

No.Gamma rays have the shortest wavelength. Wavelength and frequency are inversely proportional. When wavelength decreases, frequency increases which also increases energy.

TLDR
Long wavelengths = shorter frequency = less energy
Short wavelengths = longer frequency = more energy
by Katie Le 3K
Sun Nov 01, 2020 11:51 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: difference in p orbitals
Replies: 8
Views: 54

difference in p orbitals

In Prof. Lavelle's lecture, he writes

N, Z=7 1s^2 2s^2 2px^1 2py^1 2pz^1

I understand that its 2p^3 but how do I figure out the different px py pz?
by Katie Le 3K
Wed Oct 28, 2020 11:26 am
Forum: DeBroglie Equation
Topic: p
Replies: 19
Views: 155

Re: p

P is momentum. On our formula sheet, it says p = (mass)(velocity)
by Katie Le 3K
Wed Oct 28, 2020 11:25 am
Forum: Properties of Light
Topic: How to remember what v is in equations
Replies: 46
Views: 261

Re: How to remember what v is in equations

On our formula sheet, if you look closely, the italicized v is frequency and the normal v is velocity.
by Katie Le 3K
Tue Oct 27, 2020 11:08 pm
Forum: Photoelectric Effect
Topic: Lyman Series
Replies: 30
Views: 199

Re: Lyman Series

Yes Lyman ends with n=1. Balmer ends with n=2
by Katie Le 3K
Tue Oct 27, 2020 11:06 pm
Forum: Photoelectric Effect
Topic: Work Function
Replies: 3
Views: 41

Re: Work Function

Yes you're correct. It's easier if you take notice of what units you need to get your answer.
by Katie Le 3K
Tue Oct 27, 2020 11:04 pm
Forum: Photoelectric Effect
Topic: Photoelectric Effect
Replies: 13
Views: 119

Re: Photoelectric Effect

If the energy of a photon doesn't "match with" (less than) the work function, it just passes through the metal.
by Katie Le 3K
Sat Oct 17, 2020 9:48 pm
Forum: DeBroglie Equation
Topic: Units in Debroglie Equation
Replies: 3
Views: 16

Units in Debroglie Equation

Debroglie equation: wavelength = constant/(mass)(velocity)

Does the equation have a set unit like it always has to be in kg? and does velocity always have to be m.s^-1
by Katie Le 3K
Thu Oct 15, 2020 12:14 am
Forum: Photoelectric Effect
Topic: 10/14 Lecture Threshold Energy
Replies: 8
Views: 95

Re: 10/14 Lecture Threshold Energy

depending on the problem, itd be given to you or you have to find out. youre best bet would be to understand coneptually what the threshold means so that when a question asks you about it without outright telling you you'd know. also, threshold is not constant it depends on what substance it is
by Katie Le 3K
Thu Oct 15, 2020 12:10 am
Forum: Properties of Electrons
Topic: Lyman vs. Balmer series
Replies: 20
Views: 164

Re: Lyman vs. Balmer series

Lyman is uv light and the energy level is 1 while balmer is visible light and the energy level is 2
by Katie Le 3K
Thu Oct 15, 2020 12:09 am
Forum: Properties of Light
Topic: photons and quanta
Replies: 7
Views: 78

Re: photons and quanta

quanta is used to describe small units that are discrete so photon is quanta
by Katie Le 3K
Thu Oct 15, 2020 12:07 am
Forum: Properties of Light
Topic: Amplitude and Energy
Replies: 6
Views: 31

Re: Amplitude and Energy

Yes in terms of the wave model amplitude is related to intensity of light and number of photons
by Katie Le 3K
Thu Oct 15, 2020 12:05 am
Forum: Properties of Light
Topic: Light Intensity and Photons
Replies: 8
Views: 69

Re: Light Intensity and Photons

Intensity is in simpler terms the number of photons in light. so increasing intensity means adding more photons
by Katie Le 3K
Tue Oct 06, 2020 5:07 pm
Forum: SI Units, Unit Conversions
Topic: Rounding in Between Steps [ENDORSED]
Replies: 22
Views: 202

Re: Rounding in Between Steps [ENDORSED]

I keep a lot of decimals in my equation answers and only round at the end of your multistep equation.
by Katie Le 3K
Tue Oct 06, 2020 5:04 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Avogadro's #
Replies: 31
Views: 363

Re: Avogadro's #

You can look up a diagram called "Stoichiometry Island" on Google and it will help you figure out what formulas/constants you need to use to find your answer. Avogadro's # is used when you want to go from moles to atoms or molecules and vice versa.
by Katie Le 3K
Tue Oct 06, 2020 4:58 pm
Forum: Balancing Chemical Reactions
Topic: Combustion
Replies: 14
Views: 189

Re: Combustion

I think he was saying that those processes have similar reactions. For example, I believe they all involve O2 as a reactants and CO2 and H2O as the product.
by Katie Le 3K
Tue Oct 06, 2020 4:46 pm
Forum: Molarity, Solutions, Dilutions
Topic: Volume in Molarity Equations
Replies: 5
Views: 46

Volume in Molarity Equations

Molarity = moles/volume. Does 'v' have to be in liters or can it be in other units like ml?
by Katie Le 3K
Tue Oct 06, 2020 4:43 pm
Forum: Significant Figures
Topic: When are sig figs applied?
Replies: 12
Views: 104

Re: When are sig figs applied?

I use sig figs at the end of a multistep equation. I think it's supposed to help with the accuracy of your final answer.

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