Search found 38 matches

by victoriatanaka1C
Thu Jun 14, 2018 1:19 am
Forum: Conjugate Acids & Bases
Topic: Ammonium [ENDORSED]
Replies: 1
Views: 149

Ammonium [ENDORSED]

We know NH3 is a base, but assuming we didn't know this, how would we know that it would accept protons rather than lose them? Is it because it wants to form NH4, which is a strong acid?

And what are good acids/bases to have memorized? I didn't write down what Dr. Lavelle suggest we know...
by victoriatanaka1C
Wed Jun 13, 2018 10:42 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordination Compounds: Ligands [ENDORSED]
Replies: 3
Views: 256

Re: Coordination Compounds: Ligands [ENDORSED]

Is ligand just a special name for the thing bonded to the central atom? Like, what really is their significance?
by victoriatanaka1C
Wed Jun 13, 2018 10:38 pm
Forum: Conjugate Acids & Bases
Topic: My Understanding
Replies: 1
Views: 132

Re: My Understanding

Yes! Our textbook says:

Acid ----donates H+----> conjugate base

Base ----accepts H+----> conjugate acid
by victoriatanaka1C
Wed Jun 13, 2018 10:36 pm
Forum: Lewis Structures
Topic: Breaking the Octet Rule
Replies: 3
Views: 126

Re: Breaking the Octet Rule

And just to clarify, the elements that can break the octet rule are H, He, Li, Be, Column 13 and Row 3 and below?
by victoriatanaka1C
Sun Jun 03, 2018 11:59 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Ligands
Replies: 2
Views: 107

Re: Ligands

Will we have to know the differences between ligands? Like in class Dr. Lavelle drew cis-platinum and trans-platinum. Do we have to know keywords like cis and trans in order to draw the right version?
by victoriatanaka1C
Sun Jun 03, 2018 11:57 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Hybridization
Replies: 7
Views: 226

Re: Hybridization

In the syllabus, for Chapter 4, it says we need to know "hybridization (sp, sp2 sp3, dsp3, d2sp3) and apply this bonding model to inorganic, organic, and biological compounds (molecules, cations, and anions))." I'm just going to try to memorize, unless anyone else has any tips for figuring...
by victoriatanaka1C
Sun Jun 03, 2018 11:54 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Oxidation number
Replies: 4
Views: 142

Re: Oxidation number

I just looked at this link and it seems to cover everything! https://socratic.org/questions/how-do-y ... a-compound

I too am curious about if we'll have to have this memorized for the final...
by victoriatanaka1C
Sun May 27, 2018 11:46 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge Meaning
Replies: 5
Views: 266

Re: Formal Charge Meaning

Kind of...I think a formal charge of 0 means electrons are equally shared in covalent bonds. I'm not sure if that's the main purpose of formal charge though!
by victoriatanaka1C
Sun May 27, 2018 11:41 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Notes Wed 5/23 and Fri 5/25
Replies: 2
Views: 87

Re: Notes Wed 5/23 and Fri 5/25

Thanks so so much! My email is victoriatanaka@g.ucla.edu
by victoriatanaka1C
Sun May 27, 2018 4:58 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Notes Wed 5/23 and Fri 5/25
Replies: 2
Views: 87

Notes Wed 5/23 and Fri 5/25

Hi! I wasn't able to attend lecture last Wednesday or Friday because of health reasons. Would any of you be willing to send me the notes for these days? Thanks!
by victoriatanaka1C
Sun May 27, 2018 4:47 pm
Forum: Lewis Structures
Topic: Central atom and octet rule?
Replies: 12
Views: 493

Re: Central atom and octet rule?

The central atom can have an expanded octet if it appears in Group 3 or below. Their d-orbitals allow for bonding beyond 8 e-. There are also other exceptions to the octect rule, like Group 13 elements, H, He, Li, and Be. The octet rule is a guideline, not a hard fast rule!
by victoriatanaka1C
Mon May 21, 2018 9:34 pm
Forum: Lewis Structures
Topic: 3.59a
Replies: 1
Views: 74

Re: 3.59a

I think it's because O is slightly more electronegative, so it wants to hog that extra e- to get an octet.
by victoriatanaka1C
Mon May 21, 2018 8:52 pm
Forum: Lewis Structures
Topic: 3.59a
Replies: 1
Views: 74

3.59a

For 3.59a you're supposed to draw the Lewis structure for ClO and in the answer key it says the unpaired electron should be on the Cl. But I drew it on the O, which I thought made more sense because then the formal charge of O would be 6 - 5- 1 = 0 and Cl would be 7 - 6 - 1 = 0. In the answer key, O...
by victoriatanaka1C
Sun May 20, 2018 2:25 pm
Forum: DeBroglie Equation
Topic: De Broglie Wavelength on the Midterm
Replies: 4
Views: 202

Re: De Broglie Wavelength on the Midterm

The way I think through these problems is to first write down what I'm given and what is unknown. You're given the velocity of an electron and the mass of an electron is constant. What is unknown is the wavelength of that moving electron. Next, I look for equations that involve my given and unknowns...
by victoriatanaka1C
Sun May 20, 2018 2:14 pm
Forum: Dipole Moments
Topic: Difference between Dipole-Dipole and Dipole-Induced dipole?
Replies: 2
Views: 80

Re: Difference between Dipole-Dipole and Dipole-Induced dipole?

H-F is already a dipole, as H is delta positive and F is delta negative. N triple bond N is naturally equally charged, given N has the N charge as N. But, in the presence of H-Cl, a dipole because H is delta positive and Cl is delta negative, there is a slight pull on the charge of the Ns, making on...
by victoriatanaka1C
Sun May 20, 2018 2:10 pm
Forum: Bond Lengths & Energies
Topic: Pentane vs. 2-dimethylpropane
Replies: 3
Views: 218

Re: Friday Class

In my notes, I wrote "instantaneous dipoles in two nearby rod-shaped molecules are closer and therefore stronger than those in two nearby spherical molecules." Pentane and 2, 2-Dimethylpropane have the same molecular formula but pentane is rod-shaped. This rod shape is stronger so it's har...
by victoriatanaka1C
Sun May 20, 2018 12:23 pm
Forum: Ionic & Covalent Bonds
Topic: Phases of molecules
Replies: 1
Views: 53

Phases of molecules

In Friday, Dr. Lavelle was explaining that the increasing strength of dispersion forces explains why F2 and Cl2 are gases at room temperature while Br2 is a liquid and I2 is a solid. He also gave other examples. In the periodic table we look at in class, it says the phases of atoms, but in the perio...
by victoriatanaka1C
Sun May 20, 2018 12:16 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Relationship in periodic table and polarizability
Replies: 1
Views: 324

Relationship in periodic table and polarizability

Dr. Lavelle said polarizability depends on the number of electrons and the size of an atom or molecule. I think he said polarizability decreases across a period and increases down a group. If I made a mistake, can someone point that out? Also, can someone explain what this means. I don't quite under...
by victoriatanaka1C
Sun May 20, 2018 12:07 pm
Forum: Octet Exceptions
Topic: Empty d-orbital?
Replies: 2
Views: 110

Re: Empty d-orbital?

As far as I understand, an "empty p-orbital" just means that the ground state atom doesn't have electrons in the p-orbital but it is available for bonding. I honestly don't know why this is the case, but I'm just taking it as fact. Sorry if this doesn't really help!
by victoriatanaka1C
Sun May 06, 2018 12:27 pm
Forum: *Shrodinger Equation
Topic: Schrodinger's Equation & Orbitals
Replies: 3
Views: 179

Re: Schrodinger's Equation & Orbitals

I'm also confused about this. I have in my notes psi (x, y, z) = Energy psi (x, y, z), but also psi: s, p, d, f. Maybe the x = s, y = p, and z = d?
by victoriatanaka1C
Sun May 06, 2018 12:21 pm
Forum: Molarity, Solutions, Dilutions
Topic: Test 1 Q.1
Replies: 3
Views: 191

Re: Test 1 Q.1

And here's my solution for B! For these problems, plugging into the equation M = moles / volume is straightforward, but I think the hardest part is making sure you're using the right value for number of moles. Make sure to calculate the number of moles for the element you want by looking at its rati...
by victoriatanaka1C
Sun May 06, 2018 12:07 pm
Forum: Molarity, Solutions, Dilutions
Topic: Test 1 Q.1
Replies: 3
Views: 191

Re: Test 1 Q.1

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Here's my solution for A
by victoriatanaka1C
Sun May 06, 2018 11:44 am
Forum: Balancing Chemical Reactions
Topic: Test 1. Q 3
Replies: 1
Views: 119

Re: Test 1. Q 3

Someone told me it's a good plan to keep compunds together that appear on both sides, and my TA told me H20, in most cases, requires an even coefficient. So using those guidelines, I compared PO4 on both sides and multiplied the one on the left my 2. With this, Ca and PO4 are in balance. Now there's...
by victoriatanaka1C
Sun Apr 29, 2018 9:33 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: 2.27 [ENDORSED]
Replies: 4
Views: 177

Re: 2.27 [ENDORSED]

Orbitals and subshells are not the same thing! Shells are determined by the value of n. Subshells are determined by the value of l (which can go from 0 to the value of n-1). Orbitals are determined by the value of m (which are valued between l and -l). So if you're given n = 4 and l = 1, m can be 1,...
by victoriatanaka1C
Sun Apr 29, 2018 4:59 pm
Forum: Quantum Numbers and The H-Atom
Topic: # of electrons for a given orbital (homework 2.25)
Replies: 3
Views: 101

# of electrons for a given orbital (homework 2.25)

I'm just looking for clarification - is the number of electrons that can occupy a given orbital equal to the number of possible values of m times 2?
by victoriatanaka1C
Sun Apr 29, 2018 3:48 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Technicality for 2.19
Replies: 1
Views: 37

Technicality for 2.19

The question asks in a) for POSSIBLE values of l but in b) and c) for ALLOWED values for m.

What is the significance of this difference?
by victoriatanaka1C
Sun Apr 29, 2018 3:39 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: HW question 2.17 [ENDORSED]
Replies: 2
Views: 101

Re: HW question 2.17 [ENDORSED]

m labels the different orbitals of a subshell and its allowed values are l to -l by decrementing l by 1 every time in between (Professor Lavelle did talk about this on Wednesday, so it makes sense that you're confused). So for a), l = 0 and m can only be 0, so there is 1 orbital. In b), l = 2 so m =...
by victoriatanaka1C
Sun Apr 22, 2018 9:51 pm
Forum: Properties of Electrons
Topic: Circular Standing Waves
Replies: 2
Views: 115

Re: Circular Standing Waves

Electrons move around their nucleus in a cloud, so if we think of them moving in a perfect circle (the standing waves oscillating around the circle), there has to be a specific number of wavelengths to fit perfectly in a circle. Because there has to be a specific number of wavelengths around the cir...
by victoriatanaka1C
Sun Apr 22, 2018 3:03 pm
Forum: DeBroglie Equation
Topic: HW 1.37 [ENDORSED]
Replies: 6
Views: 275

Re: HW 1.37 [ENDORSED]

Would the answer be "the wavelength of a proton is x% larger than the wavelength of a neutron"?
by victoriatanaka1C
Sun Apr 22, 2018 2:13 pm
Forum: Photoelectric Effect
Topic: Homework Problem #33
Replies: 4
Views: 149

Re: Homework Problem #33

I'm looking for clarification for 1.33 c. When calculating the E required (in order to calculate the wavelength), you have to combine the E required to eject the e- and the energy of ejecting the e-? How do you know when looking at the question that you need to combine both? I originally solved the ...
by victoriatanaka1C
Sun Apr 22, 2018 2:10 pm
Forum: Properties of Light
Topic: Electromagnetic Spectrum [ENDORSED]
Replies: 7
Views: 204

Re: Electromagnetic Spectrum [ENDORSED]

Does anyone have any tips for remembering the ranges? I know the order of energy for parts of the electromagnetic spectrum but I'm having a hard time learning the ranges of wavelength!
by victoriatanaka1C
Sun Apr 15, 2018 9:27 pm
Forum: Molarity, Solutions, Dilutions
Topic: Molarity [ENDORSED]
Replies: 3
Views: 166

Re: Molarity [ENDORSED]

Molarity = moles of solute / volume of solute. Assuming both have 1 Liter of solution (or whatever equal number), the 0.5M solution would have more solvent then the 0.6M solution.
by victoriatanaka1C
Sun Apr 15, 2018 9:13 pm
Forum: Administrative Questions and Class Announcements
Topic: Memorizing equations [ENDORSED]
Replies: 5
Views: 228

Re: Memorizing equations [ENDORSED]

I also believe the same cover sheet we got for the first test is what we're getting for the rest of the tests! So, if I remember correctly, we didn't get the equation for molarity (and associated Minitial x Vinitial = Mfinal x Vfinal), but it seems to me that this class is very fair about equations ...
by victoriatanaka1C
Sun Apr 08, 2018 7:19 pm
Forum: Empirical & Molecular Formulas
Topic: Question F17 a
Replies: 2
Views: 97

Re: Question F17 a

(This question also applies to part b). Basically I'm asking if what I got as the empirical formula is correct and how to properly order elements if it's not.
by victoriatanaka1C
Sun Apr 08, 2018 7:14 pm
Forum: Empirical & Molecular Formulas
Topic: Question F17 a
Replies: 2
Views: 97

Question F17 a

When i solved for part a, I got C4O4Os. The solutions manual says the answer is OsC4O4. How do I determine the right order to put my answers? I've just been listing the elements in the compound in the order they appear in the question, but this is (potentially?) incorrect in this example!
by victoriatanaka1C
Sun Apr 08, 2018 5:11 pm
Forum: Empirical & Molecular Formulas
Topic: Rounding atomic weight (general question) [ENDORSED]
Replies: 8
Views: 356

Rounding atomic weight (general question) [ENDORSED]

I noticed when Prof. Lavelle is calculating molar mass of compounds (or anything involving math), he writes the mass of O as 16 g.mol-1, but H stays 1.008 g.mol-1. Is there a guideline we should follow when rounding atomic masses?
by victoriatanaka1C
Sun Apr 08, 2018 3:53 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: E. 35
Replies: 1
Views: 147

Re: E. 35

Since the question is asking for a comparison (increase), you have to divide by the original. I did it by comparing what the mass % would be if it remained hydroxyapatite throughout, which would be 100%. Then I divided fluorapatite by hydroxyapatite (504.31/502.32) and found the difference between t...
by victoriatanaka1C
Sun Apr 08, 2018 3:08 pm
Forum: Empirical & Molecular Formulas
Topic: Naming compounds
Replies: 4
Views: 162

Naming compounds

Hi. Does anyone know if we have to know how to name chemical compounds only given their name? Like in question E9, it gives us "magnesium sulfate heptahydrate." I had to look up what the molecular formula would be for it. Do we have to be able to come up with the formulas on our own / does...

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