Search found 30 matches

by Shawn Schwartz 1D
Sat Jul 23, 2016 5:26 pm
Forum: *Indicators
Topic: Indicators
Replies: 3
Views: 1134

Re: Indicators

Dr. Lavelle said in class that whatever we don't cover in class will not be required/tested on so the answer is no we do not have to know the indicators listed in the course reader because we didn't cover them in lecture.
by Shawn Schwartz 1D
Sat Jul 23, 2016 1:32 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: CH 4 Homework #9 [ENDORSED]
Replies: 3
Views: 545

Re: CH 4 Homework #9 [ENDORSED]

In order to figure out the shape of the structure, where would the lone pairs be situated ? To answer your question, the 2 lone pairs need to be situated about the central Iodine atom. Even though it is kind of strange to think to put two lone pairs around the central atom when it already has three...
by Shawn Schwartz 1D
Sat Jul 23, 2016 1:25 am
Forum: Lewis Acids & Bases
Topic: Lewis Acid vs. Lewis Base [ENDORSED]
Replies: 3
Views: 568

Re: Lewis Acid vs. Lewis Base [ENDORSED]

Roya_N wrote:This diagram/visual really helped clear up any misunderstandings I had for Lewis Acids and Bases, thank you.


You're very welcome! I'm glad that I was able to help you! :D
by Shawn Schwartz 1D
Sat Jul 23, 2016 1:21 am
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: x,y,z spots in 2P orbitals [ENDORSED]
Replies: 2
Views: 602

Re: x,y,z spots in 2P orbitals [ENDORSED]

First, the reason that the different positions occurs due to the orbitals becoming more stable and being pushed up (in terms of each orbitals energy levels. This is because the M.O. diagrams are drawn with energy increasing up the Y-AXIS upwards (from top to bottom). So, when drawing the M.O. diagra...
by Shawn Schwartz 1D
Sat Jul 23, 2016 1:10 am
Forum: Amphoteric Compounds
Topic: Bi2O3 [ENDORSED]
Replies: 1
Views: 404

Re: Bi2O3 [ENDORSED]

I found an answer to this question from a previous post: Bi_{2}O_{3} dissolves in both acidic and basic solution. With acid: Bi_{2}O_{3}+3H_{2}O+6H_{3}O(aq)\rightleftharpoons [Bi(H_{2}O)_{6}]^{3+}(aq) . With base: Bi_{2}O_{3}+3H_{2}O+2OH^{-}(aq)\rightleftharpoons 2[Bi...
by Shawn Schwartz 1D
Fri Jul 15, 2016 12:15 pm
Forum: Hybridization
Topic: HW 4.93: Hybridization of Carbon Atoms in Cyclopropane (C6H6 [ENDORSED]
Replies: 3
Views: 996

HW 4.93: Hybridization of Carbon Atoms in Cyclopropane (C6H6 [ENDORSED]

The solutions manual says that the hybridization of all the Carbon atoms in this structure is sp^3; however, I'm not really sure/don't really understand how that is true when the Carbon atoms in this structure each have 2 single bonds and 1 double bond which would result in: 1 sigma bond for each si...
by Shawn Schwartz 1D
Fri Jul 15, 2016 11:09 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Polar and Non-Polar [ENDORSED]
Replies: 1
Views: 390

Re: Polar and Non-Polar [ENDORSED]

If drawing out the dipole's for each atom in a molecular structure, you need to treat the dipoles like vectors (which means that when you draw them...the size matters because a vector has both magnitude and direction ). Thus, if there is no symmetry in the dipole's of the atoms (which comes from the...
by Shawn Schwartz 1D
Fri Jul 15, 2016 11:07 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: CH 4 Homework #9 [ENDORSED]
Replies: 3
Views: 545

Re: CH 4 Homework #9 [ENDORSED]

ICl(3O requires a total of 28 ve- dots that need to be accounted for. After giving the 3 Cl's a full octet, there are 24 ve- accounted for, so you must put two lone pairs on the Iodine to account for the total of 28 ve-. The reason that you can put the two lone pairs on the Iodine is because Iodine ...
by Shawn Schwartz 1D
Fri Jul 15, 2016 11:04 am
Forum: Determining Molecular Shape (VSEPR)
Topic: hw 4.25(d) [ENDORSED]
Replies: 2
Views: 453

Re: hw 4.25(d) [ENDORSED]

Yes, it is because of the lone pair on the Sulfur atom that contributes to SF(4)'s polarity. This region of electron density causes a pull on the overall molecule that causes the dipole moments to shift towards the lone pair. If the molecular structure didn't have a lone pair, then it would be non-p...
by Shawn Schwartz 1D
Sun Jul 10, 2016 11:51 am
Forum: Properties of Light
Topic: Midterm question Q2F [ENDORSED]
Replies: 3
Views: 664

Re: Midterm question Q2F [ENDORSED]

in a photoelectric experiment light with frequency v is shone onto a metal surface. if we only decrease the intensity of the light to half of its original value, which of the following statement is true? rease A. there won't be electron emmision any more B. the time it tkes from photo absorption to...
by Shawn Schwartz 1D
Sun Jul 10, 2016 11:35 am
Forum: Determining Molecular Shape (VSEPR)
Topic: SUMMER 2016 MIDERM
Replies: 1
Views: 441

Re: SUMMER 2016 MIDERM

Brenda Rosales 1F wrote:Does anybody know if the 5 extra points are already added to the score or will the TA's add them later ?
Thank you!


From what I was told, the 5 extra points will be added on later (onto MyUCLA), so just take your midterm score and add 5 points to it and that is your final official score!
by Shawn Schwartz 1D
Sat Jul 09, 2016 3:36 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Full Ground-State Electron Configuration? [ENDORSED]
Replies: 2
Views: 479

Re: Full Ground-State Electron Configuration? [ENDORSED]

When writing out the full ground-state electron configuration of an iron atom, does the 3d^6 go first? Yes, when writing out the full ground-state electron configuration of an iron atom, the 3d^6 would go first before the next 4s orbital, even though the 3d orbital is higher in energy than the 4s o...
by Shawn Schwartz 1D
Sat Jul 09, 2016 3:33 am
Forum: Dipole Moments
Topic: Dipole and Polarity [ENDORSED]
Replies: 3
Views: 578

Re: Dipole and Polarity [ENDORSED]

If a molecular structure has dipole charges that do not cancel each other out does that mean that it is polar? Yes, if a molecular structure's dipole charges do not cancel out, then it is polar. For example, water is polar which is why it is the amazing solvent that it is on Earth and has so many u...
by Shawn Schwartz 1D
Sat Jul 09, 2016 3:29 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular Shape v.s Name of Shape
Replies: 3
Views: 406

Re: Molecular Shape v.s Name of Shape

Basically, the main reason why you have to include both the lone pairs and the bonding pairs for the molecular geometries/shapes is because they are considered to created regions of high electron density (which cause r epulsion), hence the name: VSEP R . In naming, the regions of high electron densi...
by Shawn Schwartz 1D
Sat Jul 09, 2016 3:25 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration, Chromium
Replies: 2
Views: 1895

Re: Electron Configuration, Chromium

Chapter 3, Question 5. Give the ground-state electron configuration expected for each of the following ions: a) Cu^+ I don't understand why the answer is [Ar]3d^10. I thought it would be [Ar]3d^7.4s The title of your post says Chromium; however, the problem that you included is for Cu+ which is cop...
by Shawn Schwartz 1D
Sat Jul 09, 2016 3:08 am
Forum: Lewis Acids & Bases
Topic: Lewis Acid vs. Lewis Base [ENDORSED]
Replies: 3
Views: 568

Re: Lewis Acid vs. Lewis Base [ENDORSED]

For starters, the distinguishing factors for a Lewis Acid vs. a Lewis Base is to remember that Lewis Acids are electron acceptors while Lewis Bases are electron donors . A cid ==> A cceptor Base ==> Donor CNX_Chem_15_02_BF3-LA_img.jpg For example, in the diagram that I have attached... You can see t...
by Shawn Schwartz 1D
Sat Jul 09, 2016 2:57 am
Forum: Lewis Structures
Topic: Determining Lowest Lewis Structure
Replies: 1
Views: 3897

Re: Determining Lowest Lewis Structure

The shortcut that I use is for atoms that can break the octet rule, I would look and see how many valance electrons it has. So, for example, let's suppose that some central atom, X has 7 valence electrons. Knowing that, along with formal charge, I can determine that because this is the central atom ...
by Shawn Schwartz 1D
Sat Jul 09, 2016 2:45 am
Forum: Hybridization
Topic: Hybridization Example
Replies: 3
Views: 2242

Re: Hybridization Example

To figure this out you first need the lewis structure of HSO ^ 3- ion--that way we can determine the shape --> which will allow us to count the number of sigma bonds + the number of lone pairs. Since we want the hybridization of the Sulfur atom, it is important to note that Sulfur is the least elect...
by Shawn Schwartz 1D
Thu Jul 07, 2016 1:05 pm
Forum: Ionic & Covalent Bonds
Topic: Why is LiH more ionic than HCL? (Fall 2011, Q6B C)
Replies: 2
Views: 741

Re: Why is LiH more ionic than HCL? (Fall 2011, Q6B C)

To answer the question as to why LiH is more ionic than HCl, is it important to remember that Hydrogen (H) is a special exception to the trends in electronegativity. This is because Hydrogen is more relatable in electronegativity to He (the right-top side of the periodic table) instead of the left s...
by Shawn Schwartz 1D
Mon Jun 27, 2016 4:17 pm
Forum: Trends in The Periodic Table
Topic: Multi-electron Atoms after Z=20 Energy States [ENDORSED]
Replies: 1
Views: 321

Multi-electron Atoms after Z=20 Energy States [ENDORSED]

I would just like to confirm that I understand the following principle that was lectured on today about the energy states for the 4s and 3d orbitals: Before Z=20: 4s > (in energy) 3d After Z=20: 3d > (in energy) 4s Except for Cr & Cu? I had a little trouble following exactly which atoms have whi...
by Shawn Schwartz 1D
Mon Jun 27, 2016 4:14 pm
Forum: Trends in The Periodic Table
Topic: Lavelle's favorite periodic table
Replies: 2
Views: 2499

Re: Lavelle's favorite periodic table

Jeannie Huang 3B wrote:Mine is the rice krispy periodic table :)
(this was for my birthday a while back)
https://drive.google.com/file/d/0BzeS9b9yItnNYkVYY0Z5Y2VjWEU/view?usp=sharing

That is actually very awesome! Thank you for sharing an amazing & creative idea!
by Shawn Schwartz 1D
Mon Jun 27, 2016 4:13 pm
Forum: Limiting Reactant Calculations
Topic: Self-Test M.4A: Combustion Analysis -> Empirical Equation [ENDORSED]
Replies: 2
Views: 525

Re: Self-Test M.4A: Combustion Analysis -> Empirical Equatio [ENDORSED]

Chem_Mod wrote:you shouldn't make approximation of 1.089 to be 1. (8% difference is way too much)If you try to convert that to a integer by multiplying 11, you should get the correct answer.

Okay that makes a lot more sense. Thank you very much!!
by Shawn Schwartz 1D
Thu Jun 23, 2016 10:02 pm
Forum: Limiting Reactant Calculations
Topic: Self-Test M.4A: Combustion Analysis -> Empirical Equation [ENDORSED]
Replies: 2
Views: 525

Self-Test M.4A: Combustion Analysis -> Empirical Equation [ENDORSED]

Hi there, I was attempting to complete the self test question on example M.4 in the textbook; however, I am not sure where I messed up because I didn't get the correct answer. Question: When 0.528 g of sucrose (a compound of carbon, hydrogen, and oxygen) is burned, 0.306 g of water and 0.815 g of ca...
by Shawn Schwartz 1D
Sun Nov 29, 2015 6:00 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Video: Concentration Calculation (Quiz 3 Prep Q#8)
Replies: 2
Views: 472

Video: Concentration Calculation (Quiz 3 Prep Q#8)

Chemistry 14A Video Chemistry Community.mp4 [ 172.25 MiB | Viewed 472 times ]



By: Shawn Schwartz, Disc. 1I

YouTube Link: https://youtu.be/W4EEivftBgw
by Shawn Schwartz 1D
Wed Oct 14, 2015 1:10 am
Forum: Trends in The Periodic Table
Topic: Visual Representations of the Periodic Table Trends
Replies: 2
Views: 530

Visual Representations of the Periodic Table Trends

Thought that these may be helpful to any students struggling with visualizing the main periodic table trends (Periodicity) discussed in the textbook:
Summary_2.png
Periodicity Trends _ Compiled
by Shawn Schwartz 1D
Wed Oct 14, 2015 1:05 am
Forum: Properties of Electrons
Topic: Rydberg Formula Derivation and Units for Quiz #1
Replies: 1
Views: 490

Rydberg Formula Derivation and Units for Quiz #1

I was wondering which form of the Rydberg formula will be appropriate for calculations on the quiz. If the simplified form of v=R((\frac{1}{n{1}^{2}})-(\frac{1}{n{2}^{2}})) is used on the quiz, will we not receive full credit for the work shown in the problem?... If this is t...
by Shawn Schwartz 1D
Fri Oct 02, 2015 9:32 pm
Forum: DeBroglie Equation
Topic: De Broglie's Wave Equation for Energy (v^2)
Replies: 1
Views: 403

De Broglie's Wave Equation for Energy (v^2)

I was wondering if someone could shed some light––pun not intended––on the equation: E=p * v . I understand that this also includes momentum within it, so the velocity is actually a quantity squared ; however, how does this relate to the equation for kinetic energy? So, this question may seem elemen...
by Shawn Schwartz 1D
Fri Oct 02, 2015 9:25 pm
Forum: Properties of Light
Topic: Doing Simple Spectroscopy?
Replies: 2
Views: 485

Re: Doing Simple Spectroscopy?

While I have done this before, it was in a lab with expensive apparatuses, but I know it can be done with a fair simple DIY rig. Instructions for that can be found here http://www.livescience.com/41548-spectr"onclick="window.open(this.href);return false; ... oject.html. Good luck with your spectros...
by Shawn Schwartz 1D
Fri Oct 02, 2015 1:44 am
Forum: Properties of Light
Topic: Doing Simple Spectroscopy?
Replies: 2
Views: 485

Doing Simple Spectroscopy?

I was wondering if anyone knows or would like to share examples of labs they have completed where you have actually partook in Spectroscopy. Could you please explain how simple/complex it was to do? Are there simple, do-able, & effective ways to perform Spectroscopy without expensive equipment.....

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