Search found 41 matches
- Mon Jun 11, 2018 9:49 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Review Sessions Finals Week - Hedrick Hall? [ENDORSED]
- Replies: 6
- Views: 1001
Re: Review Sessions Finals Week - Hedrick Hall? [ENDORSED]
So will the review sessions usually in Hedrick Hall continue on Tuesday and Wednesday?
- Fri Jun 08, 2018 12:43 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: formal charge and VSEPR
- Replies: 8
- Views: 1008
Re: formal charge and VSEPR
You would subtract one.
- Wed Jun 06, 2018 10:37 pm
- Forum: Bronsted Acids & Bases
- Topic: J11c
- Replies: 4
- Views: 632
Re: J11c
For the question overall why is it that they didn't specify whether they wanted the Lewis or Bronsted acid or base? Does it matter?
- Wed Jun 06, 2018 9:30 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Polydentate
- Replies: 5
- Views: 572
Re: Polydentate
We were told only to know three specific polydentates, correct?
- Tue Jun 05, 2018 10:47 am
- Forum: Dipole Moments
- Topic: determining dipole moment
- Replies: 3
- Views: 588
Re: determining dipole moment
Yes looking at the difference in electronegativity will help to determine which which, if any, the dipole moment will move towards as well as if they will cancel. If they do, then it's non-polar and if they don't it's polar.
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- Mon Jun 04, 2018 9:13 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Hybridization
- Replies: 7
- Views: 817
Re: Hybridization
I think in general we have to be able to figure out the hybridization of compounds when they are given, and memorizing which hybridizations go with each VSEPR shape can only help.
- Thu May 31, 2018 9:13 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Problem 4.9
- Replies: 3
- Views: 446
Re: Problem 4.9
The 2 lone pairs on the I in the lewis structure does not allow for the shape to correspond to trigonal planar nor trigonal pyramidal. The VSEPR formula of AX3E2 corresponds to the t-shape.
- Wed May 30, 2018 9:50 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR Drawing
- Replies: 7
- Views: 789
Re: VSEPR Drawing
I think we're expected to be able to tell the VSEPR formula, the shape, the bond angles, hybridization, and the lewis structures based on the homework problems assigned to us.
- Tue May 29, 2018 11:55 am
- Forum: Electronegativity
- Topic: HW question 3.77
- Replies: 4
- Views: 811
Re: HW question 3.77
I think it has largely to do with the fact that your comparing electronegativities between H and F, and because F is the most electronegative element it should be the most electronegative. Also I checked the electronegativity chart because they are pretty close to one another and the difference is b...
- Tue May 29, 2018 9:55 am
- Forum: Lewis Acids & Bases
- Topic: Boron and the octet rule [ENDORSED]
- Replies: 7
- Views: 1491
Re: Boron and the octet rule [ENDORSED]
I think it's all the elements in group 13.
- Fri May 25, 2018 10:02 am
- Forum: Lewis Structures
- Topic: Multiple Compounds (3.41)
- Replies: 3
- Views: 419
Re: Multiple Compounds (3.41)
I always begin by drawing each element in the order it was given. So for your first example Carbon is given first so I would draw the carbon with the O bonded to it, this being because H tends to only make one bond so it'd be unlikely all four would be in a linear form. So, I would have a carbon who...
- Wed May 23, 2018 10:16 pm
- Forum: Lewis Structures
- Topic: Homework Problem 3.65
- Replies: 3
- Views: 415
Re: Homework Problem 3.65
I would try and remember that Oxygen usually tends to make two bonds in order to acquire the formal charge of zero
- Tue May 22, 2018 10:27 am
- Forum: Lewis Structures
- Topic: 3.39
- Replies: 5
- Views: 689
Re: 3.39
I'm still not getting how you would get the correct lewis structure for a. Can anyone explain?
- Tue May 22, 2018 10:17 am
- Forum: Lewis Structures
- Topic: 3.39 bracket question
- Replies: 2
- Views: 325
Re: 3.39 bracket question
I think you would place the brackets around the whole compound too because the charge has to do with the entire compound.
- Sun May 20, 2018 11:28 am
- Forum: Resonance Structures
- Topic: HW problem 3.45
- Replies: 4
- Views: 549
Re: HW problem 3.45
Why when doing the resonance structure can we not give Cl-N a double bond? Or can we?
- Wed May 16, 2018 8:28 pm
- Forum: Ionic & Covalent Bonds
- Topic: Naming Molecules
- Replies: 5
- Views: 572
Re: Naming Molecules
I remember him saying he's not one to emphasize remembering the names of molecules, more understanding the concept of their structures.
- Tue May 15, 2018 11:00 am
- Forum: Ionic & Covalent Bonds
- Topic: 3.33 b
- Replies: 2
- Views: 372
Re: 3.33 b
If you calculate the formal charge for the lewis structures of the two you have you will also be able to see that the correct Lewis structure equals zero, meaning its the most stable, therefore the correct one. Hope that helps.
- Tue May 15, 2018 10:00 am
- Forum: Octet Exceptions
- Topic: OCTET RULE [ENDORSED]
- Replies: 10
- Views: 1019
Re: OCTET RULE [ENDORSED]
I always think of the octet rule as, most, elements always wanting a full 8 electrons to be as stable as possible. They all want to be full like the noble gases.
- Sun May 13, 2018 3:17 pm
- Forum: Octet Exceptions
- Topic: expanded octet XeF4
- Replies: 8
- Views: 2120
Re: expanded octet XeF4
Expanded octet can only be used depending on the element's place on the periodic table, only if the element is after the 2nd row. F is on the second row, therefore cannot have an expanded octet.
- Wed May 09, 2018 4:02 pm
- Forum: Ionic & Covalent Bonds
- Topic: Memorization of Electronegativity
- Replies: 6
- Views: 937
Re: Memorization of Electronegativity
Electronegativity increases across because the element is closer to have a filled orbital. It then decreases down because the valence electrons are further away.
- Wed May 09, 2018 11:36 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Test 2 Q.4
- Replies: 3
- Views: 580
Re: Test 2 Q.4
I have the problem worked out, would it be possible for anyone to work out the steps? Just want to make sure I did it correctly.
- Tue May 08, 2018 12:44 pm
- Forum: DeBroglie Equation
- Topic: test 2, question5
- Replies: 5
- Views: 779
Re: test 2, question5
Why are suppose to use Avogadro's number for this problem?
- Sun May 06, 2018 10:42 pm
- Forum: SI Units, Unit Conversions
- Topic: #9 on Midterm Practice Review (unicorn)
- Replies: 4
- Views: 594
Re: #9 on Midterm Practice Review (unicorn)
Also I always convert the given mL to L and do the calculations, unless it specifically states the answer is wanted in mL. Also, he posted the answers under the topic and the answer he gave had the final units in L.
- Wed May 02, 2018 6:08 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Post Assessment Question
- Replies: 1
- Views: 333
Post Assessment Question
42. An excited hydrogen atom emits light with a frequency of 1.14 x 1014 Hz to reach the energy level n = 4. In what principle quantum level did the electron begin?
Can anyone explain the steps needed to solve this problem? I'm having trouble starting because only one n value was given.
Can anyone explain the steps needed to solve this problem? I'm having trouble starting because only one n value was given.
- Wed May 02, 2018 4:40 pm
- Forum: Trends in The Periodic Table
- Topic: Ionization Energy
- Replies: 4
- Views: 548
Re: Ionization Energy
Pretty sure we're focusing on the position it has on the periodic table and not specifically by any value.
- Wed May 02, 2018 12:13 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Question 2.19 b.
- Replies: 5
- Views: 373
Re: Question 2.19 b.
I had a question about part a of this problem. The question states: "How many values of the quantum number l are possible when n=7? Since l=0,1,2,..n-l is my answer of seven correct? I'm just confused because I know l indicates the subshell and because we have not talked about those above l=3(f...
- Sat Apr 28, 2018 7:51 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Electron Spin [ENDORSED]
- Replies: 4
- Views: 425
Re: Electron Spin [ENDORSED]
I'm pretty sure because each electron has a different interaction based on each state, the +1/2 and -1/2 account for the spin up and spin down
- Tue Apr 24, 2018 10:43 pm
- Forum: Einstein Equation
- Topic: Chapter 1 Question 25 [ENDORSED]
- Replies: 4
- Views: 681
Re: Chapter 1 Question 25 [ENDORSED]
So for part c since we already know the 1.00 mol of Na would we just multiply by Avogadro's number and by the E we found in a? or just by Avogadro's number?
- Mon Apr 23, 2018 11:43 pm
- Forum: Einstein Equation
- Topic: Homework number 1.25a [ENDORSED]
- Replies: 3
- Views: 563
Re: Homework number 1.25a [ENDORSED]
What units would the final answer be in?
- Mon Apr 23, 2018 4:05 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Homework Questions for Week IV
- Replies: 3
- Views: 395
Homework Questions for Week IV
Should homework questions that will be turned into our TA's this week be strictly from the list of Ch.1 questions Dr. Lavelle emailed us?
- Sat Apr 21, 2018 8:36 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Homework 1.13 [ENDORSED]
- Replies: 3
- Views: 421
Re: Homework 1.13 [ENDORSED]
You can also use the formula En= -hR/n^2 which Dr. Lavelle used in one of the previous lectures too right?
- Sat Apr 21, 2018 7:55 pm
- Forum: Properties of Light
- Topic: HW #1.7
- Replies: 5
- Views: 1354
Re: HW #1.7
I'm still having trouble with the conversion part of the question. Can anyone show me the steps for the conversion?
- Sat Apr 21, 2018 10:40 am
- Forum: Photoelectric Effect
- Topic: Photoelectric effect pre-assessment module [ENDORSED]
- Replies: 2
- Views: 323
Re: Photoelectric effect pre-assessment module [ENDORSED]
I have tried to see if there's a way but I don't think it allows us to see the answers we got correct on any pre-assessments, only on the post-assessment does it show you.
- Sat Apr 21, 2018 10:33 am
- Forum: Properties of Light
- Topic: Wavelengths
- Replies: 8
- Views: 640
Re: Wavelengths
Yes, In discussion my TA suggested we know the order of increasing wavelengths which would also help in knowing the frequency since they are inverse of one another.
- Tue Apr 17, 2018 11:06 am
- Forum: DeBroglie Equation
- Topic: Ch.1 #41 [ENDORSED]
- Replies: 7
- Views: 2363
Re: Ch.1 #41 [ENDORSED]
You have to convert the picometers into meters before plugging it into the equation right?
- Sun Apr 15, 2018 2:19 pm
- Forum: DeBroglie Equation
- Topic: Midterm Question: wavelike properties
- Replies: 6
- Views: 726
Re: Midterm Question: wavelike properties
I think it's meaning that in order to have 'measurable wavelike properties' it has to be within the range of the electromagnetic spectrum.
- Sun Apr 15, 2018 2:14 pm
- Forum: Properties of Light
- Topic: Properties of Light [ENDORSED]
- Replies: 5
- Views: 538
Re: Properties of Light [ENDORSED]
A quantum of light of wavelength is the minimum amount of energy which can be stored in an electromagnetic wave at that wavelength, which is Planck's constant h times the frequency. (E=hv)
- Wed Apr 11, 2018 10:28 pm
- Forum: Limiting Reactant Calculations
- Topic: What is the mass of AgCl produced?
- Replies: 10
- Views: 8894
Re: What is the mass of AgCl produced?
I am stuck on this problem too. I found the mol of C6H9Cl3 to be 0.004 and then continued by multiplying that my 3molAgNO3/1molC6H9Cl3 and got 0.012molAgNO3 so then I multiplied that by the molar mass 169.88g of AgNO3 but my answer isn't correct. Can anyone help?
- Tue Apr 10, 2018 3:21 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Post Assessment Question
- Replies: 2
- Views: 400
Post Assessment Question
A solution is prepared by dissolving 55.1 g of KCl in approximately 75 mL of water and then adding water to a final volume of 125 mL. What is the molarity of KCl(aq) in this solution? Why isn't it correct to apply the M1V1=M2V2 to this specific problem?
- Thu Apr 05, 2018 4:29 pm
- Forum: Limiting Reactant Calculations
- Topic: M.15
- Replies: 5
- Views: 5826
Re: M.15
For the top answer in part b) when finding the limiting reagent I got 9.45mol for Al and 7.55mol for Cl2 but noticed that in the above posted answer they got 8.33mol. Did I make a calculation error?
- Thu Apr 05, 2018 10:12 am
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: E.27
- Replies: 2
- Views: 209
E.27
Im having trouble with part b of the question. I found the grams in the H2O molecule to be 2.992x10^-23 but don't know how to approach finding the molecule number.