Search found 31 matches
- Wed Dec 05, 2018 11:35 am
- Forum: Lewis Acids & Bases
- Topic: Inductiveness vs. atomic radii
- Replies: 1
- Views: 210
Re: Inductiveness vs. atomic radii
There is not one that you should look at first. Which one is having an effect depends on the molecules your are comparing. For molecules like HF, HCl whose protonation site is directly bonded to the atoms that are being compared, you should look at atomic radius. For molecules like CCl3COOH, CH3COOH...
- Wed Dec 05, 2018 12:29 am
- Forum: Bronsted Acids & Bases
- Topic: 7th Edition 6C.21.b
- Replies: 1
- Views: 242
Re: 7th Edition 6C.21.b
Because the CH3 in acetic acid is electron donating. The CH3 contributes electron density towards the O-H bond, which makes it harder to remove the H, thus making acetic acid a weaker acid than formic acid.
- Wed Dec 05, 2018 12:20 am
- Forum: Bronsted Acids & Bases
- Topic: Acids
- Replies: 3
- Views: 480
Re: Acids
Bronsted acid is a proton donor. Lewis acid is an electron acceptor. All Brønsted-Lowry acids are Lewis acids, but the reverse is not true.
- Thu Nov 29, 2018 1:26 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Seesaw shape
- Replies: 3
- Views: 394
Re: Seesaw shape
There are three bond angles in seesaw shape: 90, 180, and between 90 and 120.
- Thu Nov 29, 2018 1:16 am
- Forum: Dipole Moments
- Topic: Dipole Dipole Interactions
- Replies: 1
- Views: 242
Re: Dipole Dipole Interactions
Generally, polar molecules have dipole dipole interactions as there are nonzero charges on the atoms.
- Tue Nov 27, 2018 11:56 am
- Forum: Quantum Numbers and The H-Atom
- Topic: H atom and degeneracy
- Replies: 1
- Views: 465
Re: H atom and degeneracy
When an atom only contains a single electron, its orbital energies depend only on the principle quantum numbers: a 2s orbital would be degenerate with a 2p orbital. The energy of 1s and 2p will be different.
- Wed Nov 21, 2018 10:33 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR
- Replies: 3
- Views: 509
Re: VSEPR
VSEPR theory applies to gases just as it applies to other molecules. For example, CH4 is a gas that has a tetrahedral shape and NH3 is also a gas that has trigonal pyramidal shape.
- Wed Nov 21, 2018 10:28 pm
- Forum: Dipole Moments
- Topic: London forces and dipole moments
- Replies: 4
- Views: 449
Re: London forces and dipole moments
I'm not sure what you mean by greater rate of dipole dipole moment, but from what I understand, London forces increase when size or mass of atoms increase.
- Tue Nov 20, 2018 12:47 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond angles
- Replies: 4
- Views: 384
Re: Bond angles
Knowing the bond angles helps you better understand the shape and structure of the molecule. This will be useful in terms of explaining some physical properties like boiling point as well.
- Wed Nov 14, 2018 10:10 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: MgO vs BaO
- Replies: 5
- Views: 3543
Re: MgO vs BaO
Since water is polar, the more polar molecule will have higher solubility. Polarity is determined by the difference in electronegativity between two atoms. Since Mg and Ba's electronegativity is 1.2 and 0.9 respectively, and O's electronegativity is 3.5, the difference between O and Ba is larger tha...
- Wed Nov 14, 2018 8:25 am
- Forum: Administrative Questions and Class Announcements
- Topic: Week 8 Discussion
- Replies: 2
- Views: 337
Re: Week 8 Discussion
I think if your discussion is on Wednesday and after then you don't. If it's before Wednesday then this depends on you TA.
- Tue Nov 13, 2018 11:24 pm
- Forum: Lewis Structures
- Topic: Homework 2.25
- Replies: 2
- Views: 298
Re: Homework 2.25
Yes, the reasoning from the electronegativity and strength of attraction perspective is the best way to explain this problem.
- Sat Nov 10, 2018 10:54 pm
- Forum: Bond Lengths & Energies
- Topic: Molecular Shapes
- Replies: 2
- Views: 371
Re: Molecular Shapes
I think the professor will discuss more about other shapes next week.
- Sat Nov 10, 2018 10:48 pm
- Forum: Ionic & Covalent Bonds
- Topic: Covalent vs Hydrogen bond in H20
- Replies: 4
- Views: 1741
Re: Covalent vs Hydrogen bond in H20
That is just a covalent bond. The hydrogen bonding in water is intermolecular.
- Sat Nov 10, 2018 10:43 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Hydrogen Bonding
- Replies: 2
- Views: 247
Re: Hydrogen Bonding
Usually hydrogen bonds form between molecules, but they can also form within a molecule. In biology, intramolecular hydrogen bonding help proteins and nucleic acids maintain specific shapes.
- Wed Oct 31, 2018 9:25 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Degenerate Orbitals
- Replies: 1
- Views: 329
Re: Degenerate Orbitals
There exist 3 degenerate 3p orbitals. No matter for 2p, 3p, or 4p, the answer is always 3 because there only exist 3 p-orbitals at each energy level. And each of the p orbital has the same energy, which means they are degenerate. The degeneracy of d orbitals would be 5 and degeneracy of f orbitals w...
- Wed Oct 31, 2018 9:20 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: 3.5 c&d
- Replies: 2
- Views: 339
Re: 3.5 c&d
When electrons start filling in the orbitals, they fill 4s first and then fill 3d because 4s has lower energy state than 3d at first. But once 4s is filled, its energy became higher than 3d. When losing electrons, electrons in higher energy levels are given out first since they are less stable.So el...
- Wed Oct 31, 2018 9:14 pm
- Forum: Properties of Electrons
- Topic: Electron Orbitals
- Replies: 1
- Views: 495
Re: Electron Orbitals
According to my TA, degeneracy simply means 'same energy'. For example, the degeneracy of p orbitals is 3.
- Tue Oct 23, 2018 11:10 pm
- Forum: Photoelectric Effect
- Topic: Module: Photoelectric Effect #25
- Replies: 1
- Views: 291
Re: Module: Photoelectric Effect #25
The answer is E=hv. This equation is actually one main experiment result of the photoelectric experiment.
- Tue Oct 23, 2018 11:08 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: m with subscript l
- Replies: 4
- Views: 575
Re: m with subscript l
It is the magnetic quantum number which tells you the orientation of the orbital. It can take the value from -l to l.
- Tue Oct 23, 2018 10:41 am
- Forum: Sigma & Pi Bonds
- Topic: determining which bonds are in a molecule
- Replies: 4
- Views: 512
Re: determining which bonds are in a molecule
Yes, by writing out the electron configuration you will be able to know the number of valence electrons, which is the key in determining what bonds are present.
- Tue Oct 16, 2018 9:44 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: 1D.13
- Replies: 2
- Views: 257
Re: 1D.13
The 7 values from 0-6 are all possible L values. Quantum numbers can be larger than 4.
- Tue Oct 16, 2018 9:38 pm
- Forum: Einstein Equation
- Topic: 1B 9 7th edition
- Replies: 2
- Views: 280
Re: 1B 9 7th edition
You can think of it this way. The energy of each photon is 4.7 x 10^-19J. If we multiply this energy by number of photons, we will get the total energy. Since now we want to get the number of photons, we do it backwards by dividing the total energy with energy per photon.
- Tue Oct 16, 2018 9:32 pm
- Forum: Properties of Light
- Topic: Finding energy
- Replies: 1
- Views: 210
Re: Finding energy
The energy produced by each photon is given by the equation E=hv, and we also know v=c/λ, so we get E=hc/λ. Then you just multiply E by the number of photons to get the total energy produced by the radiation in one second.
- Wed Oct 10, 2018 10:55 am
- Forum: Empirical & Molecular Formulas
- Topic: Writing formulas from mass compositions
- Replies: 1
- Views: 250
Re: Writing formulas from mass compositions
There is something called the Hill system, which states carbon atoms are listed first, hydrogen atoms next. All the other elements then follow hydrogen and are listed in alphabetical order. I think this rule only applies to molecular compounds. In your example, Cl should be before N because C is bef...
- Tue Oct 09, 2018 1:36 pm
- Forum: Photoelectric Effect
- Topic: Problem 1B 15(c)
- Replies: 2
- Views: 393
Re: Problem 1B 15(c)
Your answer could just be an issue of not using enough sig figs throughout the problem, but I'll walk you through the steps I did to get 8.8 nm regardless. I used the equation: KE(of electron) = energy(of photon) - threshold energy. I first solved for the KE of the electron by converting the veloci...
- Mon Oct 08, 2018 9:06 pm
- Forum: Photoelectric Effect
- Topic: Problem 1B 15(c)
- Replies: 2
- Views: 393
Problem 1B 15(c)
The velocity of an electron that is emitted from a metallic surface by a photon is 3.6*10^3 km/s. (a) What is the wavelength of the ejected electron? (b) No electrons are emitted from the surface of the metal until the frequency of the radiation reaches 2.50*10^16 Hz. How much energy is required to ...
- Tue Oct 02, 2018 1:31 pm
- Forum: Balancing Chemical Reactions
- Topic: Audio Visual Focus Topics Balancing Chemical Equations Pre Assessment
- Replies: 2
- Views: 184
Re: Audio Visual Focus Topics Balancing Chemical Equations Pre Assessment
I agree that the net moles of gas produced should be moles of gaseous products minus moles of gaseous reactants
- Sun Sep 30, 2018 11:18 pm
- Forum: Empirical & Molecular Formulas
- Topic: Problem E5
- Replies: 6
- Views: 3487
Re: Problem E5
I got the same answers as you :)
- Sat Sep 29, 2018 11:37 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Question G21 [ENDORSED]
- Replies: 5
- Views: 441
Re: Question G21 [ENDORSED]
Can you tell me the molar mass of each of the three compound you get? I have tried two periodic tables for now and I kept getting 4.57*10^-2 :(
- Fri Sep 28, 2018 11:12 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Question G21 [ENDORSED]
- Replies: 5
- Views: 441
Question G21 [ENDORSED]
On the textbook the answer to G21 part (a) is 4.58*10^-2 M. I did it multiple times and no matter how many significant figures I kept during calculation, I could only get 4.57*10^-2 M. I know the difference is very little, but this bothers me a lot... Can anyone try to do this question and see if yo...