Search found 30 matches
- Sat Jul 23, 2016 5:26 pm
- Forum: *Indicators
- Topic: Indicators
- Replies: 6
- Views: 2215
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.
- Sat Jul 23, 2016 1:32 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: CH 4 Homework #9 [ENDORSED]
- Replies: 3
- Views: 762
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...
- Sat Jul 23, 2016 1:25 am
- Forum: Lewis Acids & Bases
- Topic: Lewis Acid vs. Lewis Base [ENDORSED]
- Replies: 3
- Views: 1003
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
- 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: 1045
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...
- Sat Jul 23, 2016 1:10 am
- Forum: Amphoteric Compounds
- Topic: Bi2O3 [ENDORSED]
- Replies: 1
- Views: 581
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...
- Fri Jul 15, 2016 12:15 pm
- Forum: Hybridization
- Topic: HW 4.93: Hybridization of Carbon Atoms in Cyclopropane (C6H6 [ENDORSED]
- Replies: 3
- Views: 1658
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...
- Fri Jul 15, 2016 11:09 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Polar and Non-Polar [ENDORSED]
- Replies: 1
- Views: 531
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...
- Fri Jul 15, 2016 11:07 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: CH 4 Homework #9 [ENDORSED]
- Replies: 3
- Views: 762
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 ...
- Fri Jul 15, 2016 11:04 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: hw 4.25(d) [ENDORSED]
- Replies: 2
- Views: 640
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...
- Sun Jul 10, 2016 11:51 am
- Forum: Properties of Light
- Topic: Midterm question Q2F [ENDORSED]
- Replies: 3
- Views: 969
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...
- Sun Jul 10, 2016 11:35 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: SUMMER 2016 MIDERM
- Replies: 1
- Views: 577
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!
- Sat Jul 09, 2016 3:36 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Full Ground-State Electron Configuration? [ENDORSED]
- Replies: 2
- Views: 735
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...
- Sat Jul 09, 2016 3:33 am
- Forum: Dipole Moments
- Topic: Dipole and Polarity [ENDORSED]
- Replies: 3
- Views: 886
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...
- Sat Jul 09, 2016 3:29 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Molecular Shape v.s Name of Shape
- Replies: 3
- Views: 645
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...
- Sat Jul 09, 2016 3:25 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configuration, Chromium
- Replies: 2
- Views: 2522
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...
- Sat Jul 09, 2016 3:08 am
- Forum: Lewis Acids & Bases
- Topic: Lewis Acid vs. Lewis Base [ENDORSED]
- Replies: 3
- Views: 1003
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...
- Sat Jul 09, 2016 2:57 am
- Forum: Lewis Structures
- Topic: Determining Lowest Lewis Structure
- Replies: 1
- Views: 4292
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 ...
- Sat Jul 09, 2016 2:45 am
- Forum: Hybridization
- Topic: Hybridization Example
- Replies: 3
- Views: 4251
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...
- 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: 1054
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...
- 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: 455
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...
- Mon Jun 27, 2016 4:14 pm
- Forum: Trends in The Periodic Table
- Topic: Lavelle's favorite periodic table
- Replies: 2
- Views: 2735
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!
- Mon Jun 27, 2016 4:13 pm
- Forum: Limiting Reactant Calculations
- Topic: Self-Test M.4A: Combustion Analysis -> Empirical Equation [ENDORSED]
- Replies: 2
- Views: 958
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!!
- Thu Jun 23, 2016 10:02 pm
- Forum: Limiting Reactant Calculations
- Topic: Self-Test M.4A: Combustion Analysis -> Empirical Equation [ENDORSED]
- Replies: 2
- Views: 958
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...
- Sun Nov 29, 2015 6:08 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Video: Concentration Calculation (Quiz 3 Prep Q#8)
- Replies: 2
- Views: 537
- Sun Nov 29, 2015 6:00 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Video: Concentration Calculation (Quiz 3 Prep Q#8)
- Replies: 2
- Views: 537
- Wed Oct 14, 2015 1:10 am
- Forum: Trends in The Periodic Table
- Topic: Visual Representations of the Periodic Table Trends
- Replies: 2
- Views: 649
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:
- Wed Oct 14, 2015 1:05 am
- Forum: Properties of Electrons
- Topic: Rydberg Formula Derivation and Units for Quiz #1
- Replies: 1
- Views: 635
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...
- Fri Oct 02, 2015 9:32 pm
- Forum: DeBroglie Equation
- Topic: De Broglie's Wave Equation for Energy (v^2)
- Replies: 1
- Views: 454
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...
- Fri Oct 02, 2015 9:25 pm
- Forum: Properties of Light
- Topic: Doing Simple Spectroscopy?
- Replies: 2
- Views: 712
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...
- Fri Oct 02, 2015 1:44 am
- Forum: Properties of Light
- Topic: Doing Simple Spectroscopy?
- Replies: 2
- Views: 712
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.....