Search found 35 matches

by Brice McKeown 3D
Sat Dec 08, 2018 6:50 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: AX4E2
Replies: 1
Views: 95

AX4E2

When a molecule has the VESPR formula of AX4E2, and all of the attached atoms here the same, is the molecule that is square planar non polar because all of the dipoles cancel each other out? Or do the lone pairs being on either axis have some effect that makes it polar?
by Brice McKeown 3D
Fri Dec 07, 2018 1:03 am
Forum: Bronsted Acids & Bases
Topic: 7th edition 6A.9 Part C
Replies: 1
Views: 73

7th edition 6A.9 Part C

So the equation is CH3COOH+ NH3----> CH3CONH2+ H2O and the question is can this be classified as a reaction between a bronsted acid and base. The hint is to write the net ionic equation which I understand... but the answer key says that there is no proton transferred. I am just confused how no proto...
by Brice McKeown 3D
Mon Dec 03, 2018 3:44 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: 7th Edition Focus 9C.5b [ENDORSED]
Replies: 2
Views: 78

Re: 7th Edition Focus 9C.5b [ENDORSED]

I do not understand why not all of the oxygens (that is all three) can bind to a metal ion? Why is it only one or two?
by Brice McKeown 3D
Sun Dec 02, 2018 6:07 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: 7th edition 3F.13
Replies: 1
Views: 69

7th edition 3F.13

I am confused why a molecule with a tetrahedral shape can have two atoms bonded to the central atom closer together than other atoms. Like aren't all then bound atoms 120 degrees apart? So why does it say that option II has oppositely charged ends closest to each other?
by Brice McKeown 3D
Sat Dec 01, 2018 7:10 pm
Forum: Hybridization
Topic: 2F.7 7th Edition
Replies: 2
Views: 66

Re: 2F.7 7th Edition

Yea, you have to make sure to count both bonding pairs and lone pairs when calculating the hybridization!
by Brice McKeown 3D
Sat Dec 01, 2018 7:01 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Water molecules
Replies: 3
Views: 154

Re: Water molecules

It uses both hydrogens to create hydrogen bonds with the oxygens of other water molecules.
by Brice McKeown 3D
Sat Dec 01, 2018 6:58 pm
Forum: Hybridization
Topic: pi bonds
Replies: 5
Views: 114

Re: pi bonds

Since there are only two electrons in each of the 1s and 2s orbitals, you will never see a double bond here. And without a double bond, there will be no pi bonds!
by Brice McKeown 3D
Sat Dec 01, 2018 6:49 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: Is Hydrogen Bonding a type of Dipole-Dipole Interaction?
Replies: 5
Views: 120

Re: Is Hydrogen Bonding a type of Dipole-Dipole Interaction?

Yes, so if someone says there is hydrogen bonding present, you can assume that dipole-dipole is also present. The opposite is not true though. If it is said that dipole-dipole interactions are taking place, you cannot say that hydrogen bonding is also present without more information!
by Brice McKeown 3D
Fri Nov 23, 2018 8:03 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 2E.25 7th Edition
Replies: 1
Views: 45

2E.25 7th Edition

For A, it asks if the molecule CH2Cl2 is polar or non polar based on the Lewis structure. The answer manual has the Cl and H atoms around the central carbon which I understand... but how do you tell if when making the bond pairs off of the central carbon if the chlorines are on opposite sides of the...
by Brice McKeown 3D
Thu Nov 22, 2018 12:20 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 13
Views: 222

Re: Bond Angles

Why is it that molecules with the same VESPR formula and lone pairs present have different bond angles? For example, look at the VESPR formula AX2E. O3 has bond angles of 116.8, but SO2 has bond angles of 119.5.
by Brice McKeown 3D
Thu Nov 22, 2018 12:13 am
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Sigma and Pi Bonds
Replies: 5
Views: 119

Re: Sigma and Pi Bonds

Another thing I found helpful is that because the pi bonds are weaker they are more reactive!
by Brice McKeown 3D
Thu Nov 22, 2018 12:05 am
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Sigma and Pi Bonds
Replies: 3
Views: 79

Sigma and Pi Bonds

I am having troubles conceptualizing these two types of bonds. Does anyone have any helpful hints/tools that goes beyond what the book says? Or any good youtube videos they found to help better understand these bonds?
by Brice McKeown 3D
Wed Nov 21, 2018 11:51 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond angles for T-shaped, see-saw, and square pyramidal
Replies: 2
Views: 73

Re: Bond angles for T-shaped, see-saw, and square pyramidal

When there is a see-saw shape, the lone pair is an equatorial lone pair and it therefore repels only the electron pairs in the two axial bonds aka the two that make the 180 degree angle
by Brice McKeown 3D
Sun Nov 18, 2018 1:12 pm
Forum: Hybridization
Topic: Conceptual Question
Replies: 2
Views: 58

Re: Conceptual Question

Knowing the difference between sigma and pi bonds allows you also to know better the distribution of electron density! With pi bonds, there is electron density on either side of the internuclear axis but with the sigma bonds, there's cylindrical symmetry around the axis!
by Brice McKeown 3D
Sun Nov 18, 2018 1:05 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Octahedral
Replies: 2
Views: 74

Octahedral

Why is the shape when there is six regions of electron density, all of which are bonding pairs, octahedral and and not hexahedral? Like the shape of four regions of electron density, all of which are bonding pairs, is called tetrahedral.
by Brice McKeown 3D
Sun Nov 18, 2018 1:01 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 4 regions of electron density
Replies: 3
Views: 78

4 regions of electron density

Could someone please reiterate to me what Dr. Lavelle said about the bent shape when there is four regions of electron density and why we don't have the lone pairs at opposite sides of the central atom.
by Brice McKeown 3D
Sun Nov 11, 2018 6:55 pm
Forum: Lewis Structures
Topic: Ionic compound
Replies: 4
Views: 99

Ionic compound

When drawing the lewis structure for an ionic compound, do you just write the elements next to each other with no type of line or anything connecting the two?
by Brice McKeown 3D
Sun Nov 11, 2018 6:49 pm
Forum: Lewis Structures
Topic: Benzene
Replies: 1
Views: 67

Benzene

Is benzene the only compound that you can do the special line structure for that looks like a hexagon with a circle inside ?
by Brice McKeown 3D
Sun Nov 11, 2018 6:43 pm
Forum: Bond Lengths & Energies
Topic: Bond Length
Replies: 9
Views: 195

Bond Length

When looking at the bond length of a resonance structure, is the bond length of a resonance double bond the exact middle of the length of the single bond and double bond. Like if the double bond is 100 and the single bond is 110, is the resonance bond length 105? Or just a value in between the two l...
by Brice McKeown 3D
Sun Nov 04, 2018 12:54 pm
Forum: Trends in The Periodic Table
Topic: Problem 1F.11 (7th Edition)
Replies: 3
Views: 88

Re: Problem 1F.11 (7th Edition)

This question has me stumped as well... looking at the graph pictured in figure 1F.12 it seems like there really isn't any type of trend present, so I dont know how we are supposed to tell.
by Brice McKeown 3D
Sat Nov 03, 2018 11:25 pm
Forum: Lewis Structures
Topic: Bookwork 2B.11 part C
Replies: 1
Views: 50

Re: Bookwork 2B.11 part C

I am very stuck on this as well... do the like "parts of the formula stay together... like does the NH2 need to all be next to each other and then the COOH is all next to each other as well?
by Brice McKeown 3D
Sat Nov 03, 2018 11:17 pm
Forum: Octet Exceptions
Topic: Valence Electron
Replies: 2
Views: 76

Valence Electron

I have a question on the problem 2A.1 from the seventh edition... why when asked to give the number of valence electrons (including d electrons) does Sb have 5 valence electrons when it has 10 electrons in the 4d shell.... and then Mn has 7 and you include its d block electrons? Why do some include ...
by Brice McKeown 3D
Sun Oct 28, 2018 9:44 pm
Forum: Ionic & Covalent Bonds
Topic: Atomic Radius Decreasing
Replies: 2
Views: 32

Re: Atomic Radius Decreasing

When electrons are added, there is a greater negative charge. This greater negative charge is more so attracted to the positive nucleus, so the radius is therefore smaller.
by Brice McKeown 3D
Sun Oct 28, 2018 9:41 pm
Forum: Trends in The Periodic Table
Topic: Atomic Radius
Replies: 4
Views: 56

Atomic Radius

In lecture it was said that anions are always larger than their parent atoms... I am confused because wouldn't adding electrons create a stronger pull of the electrons towards the nucleus, thus making the anion smaller?
by Brice McKeown 3D
Sun Oct 28, 2018 9:24 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: nodal/radial planes
Replies: 5
Views: 121

Re: nodal/radial planes

Hi, wanted to ask if the wave function equaling zero is basically another way of saying no electrons will be found at that location?
by Brice McKeown 3D
Sun Oct 21, 2018 9:34 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Re: Heisenberg Uncertainty Principle
Replies: 2
Views: 59

Re: Heisenberg Uncertainty Principle

It is not possible to know both at the same time. You can only know one or the other, not both of them simultaneously!
by Brice McKeown 3D
Sun Oct 21, 2018 5:23 pm
Forum: Properties of Light
Topic: Intensity vs energy
Replies: 6
Views: 143

Re: Intensity vs energy

Just read over this in the book and thought it may ne helpful... intensity is about the number of photons, and when looking at E=hv, the E is the amount of energy of each photon individually.
by Brice McKeown 3D
Sun Oct 21, 2018 5:09 pm
Forum: Properties of Light
Topic: Wavelengths and frequencies
Replies: 10
Views: 152

Re: Wavelengths and frequencies

Does anyone know of examples of infrared radiation?
by Brice McKeown 3D
Sun Oct 21, 2018 4:57 pm
Forum: Photoelectric Effect
Topic: Work Function
Replies: 16
Views: 193

Re: Work Function

Also, I am a little confused on what it means when the electron is ejected from the metal. Like is it light? Like what is the purpose of the electron being ejected?
by Brice McKeown 3D
Sun Oct 21, 2018 4:53 pm
Forum: Photoelectric Effect
Topic: Work Function
Replies: 16
Views: 193

Re: Work Function

Could someone reiterate to me what Dr. Lavelle said about the 1/2mv^2 when the energy supplied by a photon (hv) is equal to the work function (phi).
by Brice McKeown 3D
Sun Oct 21, 2018 4:48 pm
Forum: Einstein Equation
Topic: The symbol v?
Replies: 16
Views: 414

Re: The symbol v?

In response to Josie, I think on a test, TAs aren't looking to mark you down because your nu looks like "v." I'd say just try your best to make it curvy.
by Brice McKeown 3D
Sun Oct 07, 2018 6:24 pm
Forum: Significant Figures
Topic: Significant Figures
Replies: 2
Views: 86

Re: Significant Figures

An example of this would be the number .00300. In scientific notation, this would be 3.00 x 10^-3, and would have three significant figures.
by Brice McKeown 3D
Sun Oct 07, 2018 6:19 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Avogadro's Number
Replies: 9
Views: 201

Re: Avogadro's Number

In regard to Lily Smith's question, an atom is the most basic unit of the element. A molecule is when different atoms are bonded together. For example, look at a water molecule. It is made up of hydrogen and oxygen atoms.
by Brice McKeown 3D
Sun Oct 07, 2018 6:12 pm
Forum: SI Units, Unit Conversions
Topic: Exam and Homework Problems
Replies: 2
Views: 88

Re: Exam and Homework Problems

Yes, our first test is in section this coming up week- the week of 10-08. As for the homework, I believe that it will be the problems from quantum mechanics.

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