Search found 41 matches
- Fri Dec 07, 2018 5:50 pm
- Forum: Administrative Questions and Class Announcements
- Topic: test questions
- Replies: 1
- Views: 281
Re: test questions
8 questions with multiple parts each.
- Mon Dec 03, 2018 2:07 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Ligand names
- Replies: 7
- Views: 746
Re: Ligand names
I found a quizlet for the ligand names from Chemistry Community 2016. The link is below:
https://quizlet.com/IsayanNatalie/folde ... y-14a/sets
https://quizlet.com/IsayanNatalie/folde ... y-14a/sets
- Mon Dec 03, 2018 12:38 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: cis and trans
- Replies: 1
- Views: 251
Re: cis and trans
Drawing the lewis structure and then writing the name of the ligand will help you to distinguish whether it is a cis or trans molecule.
- Mon Dec 03, 2018 12:34 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Calculating pH
- Replies: 3
- Views: 359
Re: Calculating pH
pH can also be calculated by this formula: pH = -log[H+]
- Tue Nov 27, 2018 1:46 pm
- Forum: Dipole Moments
- Topic: Hydrogen Bonding Strength
- Replies: 2
- Views: 342
Re: Hydrogen Bonding Strength
Hydrogen bonding is a strong intermolecular forces because it occurs between the hydrogen atom of one molecule and another atom of another molecule that has a high electronegativity value.
- Tue Nov 27, 2018 1:41 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Size and Strength of Attractive forces
- Replies: 2
- Views: 338
Re: Size and Strength of Attractive forces
As you increase the molar mass of a molecule, you are increasing the number of electrons in that molecule which then increases the molecule's attraction to other molecules, thus resulting in stronger London Dispersion Forces.
- Tue Nov 27, 2018 1:24 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: ligands and dentates
- Replies: 3
- Views: 397
Re: ligands and dentates
A ligand is an atom or molecule attached to a central atom, usually a metallic element, in a coordination or complex compound. Ligands must have one or more lone pairs, they bind at: 1 site---> donate 1e- pair ---> Monodentate 2 sites--->donate 2e- pair ---> Bidentate 3 sites--->donate 3e- pair ----...
- Tue Nov 27, 2018 1:16 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: T shaped
- Replies: 6
- Views: 558
Re: T shaped
AX3E2 means that the central atom is bonded to 3 atoms and has 2 lone pairs, since there are 2 lone pairs instead of 1, the bond angles change and therefore the shape changes from trigonal planar to T-shape
- Mon Nov 19, 2018 9:00 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Determining bond type
- Replies: 4
- Views: 333
Re: Determining bond type
Single Bond = 1 sigma bond
Double Bond = 1 sigma bond + 1 pi bond
Triple Bond = 1 sigma bond + 2 pi bonds
Double Bond = 1 sigma bond + 1 pi bond
Triple Bond = 1 sigma bond + 2 pi bonds
- Mon Nov 19, 2018 4:08 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Double bonds
- Replies: 8
- Views: 800
Re: Double bonds
Double bonds are seen as single bonds when you use the VESPR model, double bonds do not affect the VESPR model.
- Tue Nov 13, 2018 12:42 pm
- Forum: Student Social/Study Group
- Topic: Homework 6
- Replies: 5
- Views: 614
Re: Homework 6
Daisy Valdez 4G wrote:What problems are we answering for homework for week 7?
For Week 7, we are answering problems from Outline 4 (Chapter 4 for 6th Edition).
https://lavelle.chem.ucla.edu/wp-conten ... ucture.pdf
- Tue Nov 13, 2018 12:22 pm
- Forum: Administrative Questions and Class Announcements
- Topic: 14B Co-Requisites
- Replies: 4
- Views: 774
Re: 14B Co-Requisites
I don't think "my ucla" will let you enroll in Chem14B if you have not fulfilled the requirements. For Chem14B, you need to have taken Math 3B/31B or LS30B before or you could also take Math 3B/31B or LS 30B with Chem14B at the same time. Unfortunately, because you have not started the mat...
- Tue Nov 13, 2018 12:18 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Polar vs. NonPolar
- Replies: 5
- Views: 575
Re: Polar vs. NonPolar
Polarity depends on the electronegativity difference between two elements, if you go across the periodic table, the electronegativity increases and if you go towards the left of the periodic table, the electronegativity decreases, for example, the electronegativity difference of Cl2 would be 0 since...
- Tue Nov 06, 2018 3:08 pm
- Forum: Ionic & Covalent Bonds
- Topic: O vs N [ENDORSED]
- Replies: 4
- Views: 485
Re: O vs N [ENDORSED]
Ionization energy increases across a table because the valence shell of the elements as you go towards the right is nearly filled whereas as, as you go towards the left, the electrons have a low ionization energy from their willingness to lose electrons and become cations which is why Oxygen has a l...
- Tue Nov 06, 2018 2:56 pm
- Forum: Electronegativity
- Topic: Electron affinity
- Replies: 5
- Views: 569
Re: Electron affinity
Like electronegativity, electron affinity increases across a period and up a group because the electrons added to energy levels become closer to the nucleus, thus a stronger attraction between the nucleus and its electrons.
- Tue Nov 06, 2018 2:52 pm
- Forum: Empirical & Molecular Formulas
- Topic: Assumption of 100g
- Replies: 2
- Views: 1475
Re: Assumption of 100g
Sometimes the percentages don't add up to a 100 so you have to multiply the mass of each element by the molar mass so that the mass of all elects equal 1 to 100.
- Tue Nov 06, 2018 2:50 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal Charge of Oxygen
- Replies: 6
- Views: 1595
Re: Formal Charge of Oxygen
The formal charge depends on the arrangement of electrons around the element. Maybe Oxygen was arranged in a way in which there were more lone pairs than shared pairs which caused it to have a negative formal charge.
- Tue Oct 30, 2018 4:18 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: 1E.13
- Replies: 3
- Views: 433
Re: 1E.13
Start removing electrons from the s-orbital because the d-orbital is best stable when it is half or full-filled.
- Tue Oct 30, 2018 4:17 pm
- Forum: Lewis Structures
- Topic: Dots in Lewis Stucture
- Replies: 14
- Views: 1168
Re: Dots in Lewis Stucture
The order doesn't matter but first put one electron on each side and then start adding more when you have filled all sides with 1 electron.
- Tue Oct 30, 2018 12:08 pm
- Forum: Ionic & Covalent Bonds
- Topic: HW 3.87 6TH EDITION
- Replies: 1
- Views: 268
Re: HW 3.87 6TH EDITION
CF4 because it has the shortest bond since short bonds=strong bonds
- Mon Oct 22, 2018 12:36 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Shielding [ENDORSED]
- Replies: 15
- Views: 2032
Re: Shielding [ENDORSED]
Hello everyone, I'm struggling a bit with this concept. In the hw, it told us to find the ground state of elements (ex: Bi which has 83 electrons) and then the answer was [Xe]4f^(14)5d^(10)6s^(2)6p^(3). When it comes to elements with a high number of electrons is there another way to go about this ...
- Mon Oct 22, 2018 12:31 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Chem Community Due Date
- Replies: 6
- Views: 625
Re: Chem Community Due Date
Due date is midnight of Sunday.
- Mon Oct 22, 2018 12:29 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configuration
- Replies: 5
- Views: 447
Re: Electron Configuration
Starting with the Nobel gas should be fine.
- Mon Oct 22, 2018 12:18 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test Average
- Replies: 4
- Views: 403
Re: Test Average
michellebui_3L wrote:Where can you check the test average?
I think you will have to ask your TA what the test average is.
- Fri Oct 19, 2018 7:38 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: 4th Quantum number m subscript s [ENDORSED]
- Replies: 1
- Views: 275
Re: 4th Quantum number m subscript s [ENDORSED]
m subscript s is the electron spin quantum number, the electron can spin in two directions, +1/2 (spin up) or -1/2 (spin down).
- Fri Oct 19, 2018 1:55 pm
- Forum: Properties of Light
- Topic: Test 2 [ENDORSED]
- Replies: 15
- Views: 1178
Re: Test 2 [ENDORSED]
Brandon Mo 1J wrote:On the class website, it says, "Test 2 covers all quantum material up to and including quantum numbers."
Does this mean that there will not be anything about orbitals or anything in chapter 2 (6th edition)?
I think quantum numbers are in chapter 2.
- Wed Oct 17, 2018 2:02 pm
- Forum: Properties of Light
- Topic: Test 2 [ENDORSED]
- Replies: 15
- Views: 1178
Re: Test 2 [ENDORSED]
I think all of "Outline 2: The Quantum World" will be tested.
- Wed Oct 17, 2018 1:57 pm
- Forum: Student Social/Study Group
- Topic: Test Grades
- Replies: 4
- Views: 532
Re: Test Grades
I think the test will be passed back to you during the discussion after the week you took the test.
- Wed Oct 17, 2018 12:45 pm
- Forum: Student Social/Study Group
- Topic: Past Final Exams
- Replies: 6
- Views: 728
Re: Past Final Exams
Can anyone email to me as well? mayaal.khan@yahoo.com
- Wed Oct 17, 2018 12:24 pm
- Forum: Properties of Light
- Topic: Mnemonic for em spectrum
- Replies: 2
- Views: 228
Re: Mnemonic for em spectrum
Thank you so much for posting this!!
- Wed Oct 17, 2018 12:19 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Required knowledge for test/midterm [ENDORSED]
- Replies: 17
- Views: 1335
Re: Grade [ENDORSED]
hey, so if I didn't do too well on the first test and I mean not well at all, will getting good scores on the next tests improve my grade? The tests don't weigh as much as the midterm and final do, if you do well on the midterms and final, and one of the three tests, then you are fine. The followin...
- Mon Oct 15, 2018 2:58 pm
- Forum: Properties of Light
- Topic: List Of Equations
- Replies: 2
- Views: 127
Re: List Of Equations
Speed of light, c=λv, c=3.00*10^8 Momentum, p=mv Energy, E=pv Wavelength, lambda λ Planck's Constant, h=6.626 x 10^-34 joule*seconds Bohr Frequency Condition, ΔE=hv E(photon)=threshold energy-Ek En=-hR/n^2 Rydberg constant: R=3.29*10^15Hz Difference in energy levels, ΔE=E(final)-E(initial) De Brogli...
- Mon Oct 15, 2018 2:18 pm
- Forum: Student Social/Study Group
- Topic: 6th Edition Answers
- Replies: 2
- Views: 1212
Re: 6th Edition Answers
You can also check out the solutions manual from Powell library for an hour.
- Mon Oct 15, 2018 2:17 pm
- Forum: Properties of Electrons
- Topic: Constructive vs Destructive
- Replies: 3
- Views: 257
Re: Constructive vs Destructive
Constructive: Two waves combine to form a larger wave that has an amplitude which is larger than the amplitudes of the initial waves.
Destructive: Two waves combine but cancel out to form a smaller wave that has an amplitude which is smaller than the amplitudes of the initial waves.
Destructive: Two waves combine but cancel out to form a smaller wave that has an amplitude which is smaller than the amplitudes of the initial waves.
- Tue Oct 09, 2018 3:35 pm
- Forum: Balancing Chemical Reactions
- Topic: Element Names & Symbols
- Replies: 2
- Views: 379
Re: Element Names & Symbols
My TA said that a periodic table will be given to you on the day of the test and Mr. Lavelle said that you don't need to memorize any polyatomic ions.
- Tue Oct 09, 2018 3:32 pm
- Forum: SI Units, Unit Conversions
- Topic: How does grading for discussion posts work?
- Replies: 80
- Views: 8139
Re: How does grading for discussion posts work?
I think that "in order for you to receive the 3 points for the discussion, you need to either post a question, answer a question or put a comment relevant to the question on a post, 3 times a week." that's what one of the TA's told me. Are the posts due by the time we have our discussion ...
- Tue Oct 09, 2018 3:29 pm
- Forum: Empirical & Molecular Formulas
- Topic: when to multiply empirical formula [ENDORSED]
- Replies: 9
- Views: 4441
Re: when to multiply empirical formula [ENDORSED]
You need to multiple the answer by the smallest possible number which would turn the answer to a whole number. For example, if your answer is 1.33, you will have to multiply it by 3 to get 4.
- Fri Oct 05, 2018 9:07 pm
- Forum: Limiting Reactant Calculations
- Topic: H11
- Replies: 1
- Views: 164
Re: H11
Balance the first equation: 3 Fe2O3 + CO --------> 2 Fe3O4 + CO2 Balance the second equation: Fe3O4 + 4CO -------> 3 Fe + 4 CO2 We don't bring the moles of Fe3O4 and CO2 in the second equation because they are reactants not products in the second equation and the second question is now a completely ...
- Fri Oct 05, 2018 8:56 pm
- Forum: SI Units, Unit Conversions
- Topic: How does grading for discussion posts work?
- Replies: 80
- Views: 8139
Re: How does grading for discussion posts work?
I think that "in order for you to receive the 3 points for the discussion, you need to either post a question, answer a question or put a comment relevant to the question on a post, 3 times a week." that's what one of the TA's told me.
- Fri Oct 05, 2018 8:51 pm
- Forum: Properties of Light
- Topic: Review of high.school quantum clarification
- Replies: 1
- Views: 95
Re: Review of high.school quantum clarification
The higher the atomic number of an atom is, the higher you go up the energy levels. Energy levels are counted as whole numbers starting from 1. The atom, Carbon, contains 6 electrons which can be fitted in 2 energy levels. But, the atom, Aluminum, contains 13 electrons which can be fitted in to 3 en...
- Fri Oct 05, 2018 8:39 pm
- Forum: Balancing Chemical Reactions
- Topic: Balancing reactions tips
- Replies: 29
- Views: 2039
Re: Balancing reactions tips
I would suggest writing the numbers down under the reaction sign and solving them right there. I will provide you with an example: So, balance H2 + O2 ------> H2O by writing down the numbers of moles each reactant and product has. Having the moles written down 2 =H= 2 2 =O= 1 makes it easy for you t...