Search found 31 matches

by kendallbottrell
Mon Jun 04, 2018 10:09 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: 17.33 - Polydentate ligands
Replies: 1
Views: 98

17.33 - Polydentate ligands

I have noticed that when determining if a molecule is polydentate or not, atoms that are attached to the central atom by double bonds do not "count" as ligands. For example, C204 2-, is bidentate even though it has four attached oxygen atoms because two of them are bonded by double bonds. ...
by kendallbottrell
Mon Jun 04, 2018 12:37 pm
Forum: Bond Lengths & Energies
Topic: Ionic Character
Replies: 3
Views: 659

Re: Ionic Character

Ionic character is determined in terms of "greater ionic character" and "lower ionic character". If a molecule has increasing or a higher difference in electronegativities, then there is a greater ionic character. If the difference in electronegativity is decreasing (becoming mor...
by kendallbottrell
Mon Jun 04, 2018 12:25 pm
Forum: Hybridization
Topic: Question 4.25 Part A
Replies: 2
Views: 87

Re: Question 4.25 Part A

You have to figure out the 3-D structure and picture it to realize the orientation of the Cl atoms. Even if you do put them opposite of each other on the Lewis structure, on the VSEPR model, the Cl atoms would not be opposite of each other, and therefore not cancel.
by kendallbottrell
Fri Jun 01, 2018 12:57 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 4.25 a
Replies: 2
Views: 103

Re: 4.25 a

When you're doing polar/nonpolar problems, it is important to think of the 3D model/shape because you could see that no matter where you put the H or Cl, dipole moments will not cancel each other. If you only look at the Lewis structure, then you can get confused because it would look like they woul...
by kendallbottrell
Tue May 29, 2018 10:47 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Cancelling out dipole moments
Replies: 3
Views: 201

Re: Cancelling out dipole moments

If they are opposite of each other (180˚) then they cancel. If they are anything less than 180˚, they do not cancel.
by kendallbottrell
Thu May 24, 2018 11:17 am
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarity
Replies: 2
Views: 200

Re: Polarity

"Something that is highly polarizable means that it is susceptible to being distorted causing a dipole to form. A larger atom is more polarizable than a smaller one because its outer electrons are less tightly bound and its electron cloud is more likely to be distorted by, say, a cation." ...
by kendallbottrell
Thu May 24, 2018 11:15 am
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizing power vs polarizability
Replies: 2
Views: 216

Re: Polarizing power vs polarizability

Polarizing power is the ability to distort electron clouds and polarizability to the extent to which an electron cloud is distorted. Cations have polarizing power because the small atoms with positive charge attract and distort the electrons of an anion. Anions are polarizable because their electron...
by kendallbottrell
Tue May 22, 2018 10:08 pm
Forum: Electronegativity
Topic: Trends? [ENDORSED]
Replies: 10
Views: 622

Re: Trends? [ENDORSED]

Jordanmarshall wrote:So why is Oxygen more electronegative than Chlorine?


The simple answer is that going across the periodic table has a less significant impact on electronegativity than going down it does.
by kendallbottrell
Tue May 22, 2018 10:00 pm
Forum: Lewis Structures
Topic: lowest energy & most stable Lewis structures
Replies: 4
Views: 556

Re: lowest energy & most stable Lewis structures

To choose the most stable Lewis structure with the lowest energy, calculate the formal charges for all the atoms and choose the molecule that has all of them closest to zero. This ties into resonance structures - for example, if you have charges on one form of -2, +1, -1 and on another form 0,+1,0, ...
by kendallbottrell
Tue May 22, 2018 9:56 pm
Forum: Lewis Structures
Topic: Lewis Structure tips?
Replies: 2
Views: 144

Re: Lewis Structure tips?

For larger organic molecules (with lots of C,H,O,N) a TA suggested doing the Lewis structure and leaving the hydrogens off at first, then calculating the formal charge, and then adding the H atoms where they are needed to neutralize the formal charges. This was very efficient and it helped me a lot,...
by kendallbottrell
Fri May 18, 2018 5:20 pm
Forum: Lewis Structures
Topic: Naming compounds
Replies: 3
Views: 181

Re: Naming compounds

A couple TA's have suggested memorizing common polyatomic ions, not for the test/exams but just for the future! They are really helpful with naming!
by kendallbottrell
Thu May 17, 2018 1:54 pm
Forum: Coordinate Covalent Bonds
Topic: Coordinate Covalent Bonds
Replies: 4
Views: 431

Re: Coordinate Covalent Bonds

Coordinate covalent bonds are where both of the electrons that form the bond originate from the same atom.
by kendallbottrell
Thu May 17, 2018 1:47 pm
Forum: Lewis Structures
Topic: Finding a Lewis Structure with the Lowest Energy
Replies: 5
Views: 198

Re: Finding a Lewis Structure with the Lowest Energy

Typically I bond the elements together and then distribute the electrons and then calculate the formal charges. If the formal charges are not close enough to zero, I redistribute some electrons between the elements in the form of bonds (double, triple, etc). And then recalculate the formal charges.
by kendallbottrell
Thu May 17, 2018 1:21 pm
Forum: Trends in The Periodic Table
Topic: Electron Repulsion and Trends
Replies: 1
Views: 141

Re: Electron Repulsion and Trends

The more electrons there are, the stronger the electron repulsion. A larger cloud and more electrons would mean that the electron repulsion is high and for those atoms, it would be easier to lose the electrons, especially in the outer shells. This means that the elements with larger atomic radii als...
by kendallbottrell
Thu May 10, 2018 12:32 pm
Forum: Octet Exceptions
Topic: Octet exceptions and Formal charges.
Replies: 6
Views: 389

Re: Octet exceptions and Formal charges.

A lot of time you can use the idea of symmetry when doing bonding questions, but just to make sure you're actually correct, it is important to do the formal charge calculations. From there you would be able to tell if the structures have resonances easier too.
by kendallbottrell
Sun May 06, 2018 12:18 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Importance of Nodal Planes
Replies: 1
Views: 112

Importance of Nodal Planes

Why are nodal planes important to know? What information do they provide us? Would understanding the shapes help us understand energy levels or orbitals at all?
by kendallbottrell
Sun May 06, 2018 12:09 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Switching 3d and 4s
Replies: 6
Views: 312

Re: Switching 3d and 4s

3d actually does not have a higher energy than 4s, which is why it must be placed before 4s and 4p when writing out the electron configurations. If you follow the pattern across the periodic table, you will be able to see the corresponding energy levels. There is 3s and 3p before 3d, so that means t...
by kendallbottrell
Sun May 06, 2018 12:01 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Configuration of Fe
Replies: 2
Views: 119

Re: Configuration of Fe

Remember that it is very likely you will be able to use the "shorthand" - [Ar] 3d^6 4s^2. If it helps, a TA suggested writing it out the way you see it and then rearranging the the d orbital before the s orbital.
by kendallbottrell
Tue Apr 24, 2018 11:04 pm
Forum: Einstein Equation
Topic: converting from keV to joules
Replies: 7
Views: 303

Re: converting from keV to joules

You do not have to memorize that! The conversion of eV to J is given, and as for the k part, you would just use the conversion of (1000J / 1kJ) - because of the prefix kilo.
by kendallbottrell
Tue Apr 24, 2018 11:02 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg [ENDORSED]
Replies: 4
Views: 193

Re: Rydberg [ENDORSED]

Just the energy difference by itself can be stated as a negative number because, like you said, it just shows that light was being emitted. However, if you want to find the wavelength, you need to omit the negative signs because there is no such thing as a negative wavelength - same thing goes for f...
by kendallbottrell
Tue Apr 24, 2018 11:00 pm
Forum: Properties of Electrons
Topic: Information Provided on Exam
Replies: 6
Views: 308

Re: Information Provided on Exam

As far as I know, you will not be provided the wavelengths, so you should know the general ranges. You most likely will not need to know the specific colors of visible light, like red or green. Also, it may be helpful to know the spectrum in order of lowest to highest frequency.
by kendallbottrell
Wed Apr 18, 2018 1:28 pm
Forum: Properties of Light
Topic: The speed of light
Replies: 4
Views: 151

Re: The speed of light

Luis Avalos 1D wrote:In a vacuum, yes. The only thing that's different is their frequencies & wavelengths I believe.


What does it necessarily mean when one says "in a vacuum"?
by kendallbottrell
Wed Apr 18, 2018 1:25 pm
Forum: Properties of Light
Topic: Question 1.11
Replies: 2
Views: 118

Re: Question 1.11

The lower energy level in this context is referring to the level that each series starts at. UV light corresponds to n=1, visible light corresponds to n=2, and infrared light corresponds to n=3. When you do problems with the different series, when they say "lower energy level", you must as...
by kendallbottrell
Wed Apr 18, 2018 1:19 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Wave and Particle Properties of Electrons and Photons
Replies: 1
Views: 55

Re: Wave and Particle Properties of Electrons and Photons

An electron is a particle. Light, however, has properties of both waves and particles, which is what the experiments we reviewed in class proved.
by kendallbottrell
Sun Apr 15, 2018 6:06 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Homework 1.13 [ENDORSED]
Replies: 3
Views: 157

Re: Homework 1.13 [ENDORSED]

Also, the question should have specified which one was n1 and which was n2, so don't get confused! It is supposed to be { 1/4 - 1/16}, not the other way around.
by kendallbottrell
Thu Apr 12, 2018 5:33 pm
Forum: Molarity, Solutions, Dilutions
Topic: Units - L or mL? [ENDORSED]
Replies: 15
Views: 632

Re: Units - L or mL? [ENDORSED]

When you're using the conc=moles/vol, you need to use liters. But when you you're using the M1V1=M2V2 equation, you just need to keep all of the units the same, so essentially you can use mL instead of L.
by kendallbottrell
Thu Apr 12, 2018 5:26 pm
Forum: SI Units, Unit Conversions
Topic: Correct Units?? [ENDORSED]
Replies: 8
Views: 320

Re: Correct Units?? [ENDORSED]

A good rule of thumb is following the units the problem gives when stating the initial amounts. If they are initially given in kg, then they typically expect your answer to also be in kg.
by kendallbottrell
Thu Apr 12, 2018 5:21 pm
Forum: Significant Figures
Topic: Sig fig simple question [ENDORSED]
Replies: 5
Views: 245

Re: Sig fig simple question [ENDORSED]

Yes, when multiplying and dividing in a problem, you round to the least number of significant figures in the problem. In addition and subtraction, you round to the least number of decimals in the problem.
by kendallbottrell
Mon Apr 09, 2018 12:01 am
Forum: SI Units, Unit Conversions
Topic: SI units [ENDORSED]
Replies: 6
Views: 404

Re: SI units [ENDORSED]

There are charts in the back of the book that will help with memorizing important conversions. That is where you will find the most commonly used ones in problems.
by kendallbottrell
Sun Apr 08, 2018 11:59 pm
Forum: Balancing Chemical Reactions
Topic: Another Way to Balance
Replies: 7
Views: 283

Another Way to Balance

Is there another way to balance equations that doesn't involve just "guess and check"? Maybe something that is more systematic?
by kendallbottrell
Sun Apr 08, 2018 11:57 pm
Forum: Significant Figures
Topic: Basic Sig Figs
Replies: 13
Views: 1021

Re: Basic Sig Figs

Is maintaining significant figures necessary in this class? I can't remember if he mentioned it. If so, I would need a refresher..

Go to advanced search