Search found 29 matches
- Thu Dec 06, 2018 11:47 am
- Forum: Bronsted Acids & Bases
- Topic: Distinguishing bronsted acids vs bases
- Replies: 3
- Views: 994
Distinguishing bronsted acids vs bases
When given an equation (for ex: HNO2 + HPO4 ^2- <=> NO2^- + H2PO4^-), how can you tell which one is going to be the bronsted acid and which one will be the bronsted base? Especially if you weren’t given the products? I know that a bronsted acid is the proton donor and a bronsted base is a proton acc...
- Thu Dec 06, 2018 11:41 am
- Forum: Bronsted Acids & Bases
- Topic: Donating H protons
- Replies: 2
- Views: 367
- Sun Dec 02, 2018 2:22 pm
- Forum: Administrative Questions and Class Announcements
- Topic: MIDTERM PRACTICE - Garlic Bread Review Session [ENDORSED]
- Replies: 121
- Views: 16565
Re: MIDTERM PRACTICE - Garlic Bread Review Session [ENDORSED]
Will you be posting a similar review sheet for the final?
- Tue Nov 27, 2018 1:24 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Polarizability
- Replies: 3
- Views: 410
Re: Polarizability
Polarizability is how easily the electron cloud of an atom (usually a large anion) is distorted by another atom (usually a small highly charged cation). The atom causing the distortion (the cation) has polarizing power, which increases as the atom becomes smaller and more highly charged. The atom th...
- Tue Nov 27, 2018 1:20 pm
- Forum: Sigma & Pi Bonds
- Topic: Pi bonds and hybridization
- Replies: 2
- Views: 301
Pi bonds and hybridization
Can pi bonds be hybridized? Since they're in a different plane than the sigma bonds I'm not sure. Also, are all sigma bonds hybridized?
- Wed Nov 21, 2018 12:00 pm
- Forum: Electronegativity
- Topic: Electronegativity and Polarity
- Replies: 3
- Views: 441
Re: Electronegativity and Polarity
They’re inverses! As one inc, the other dec, and vice versa.
- Wed Nov 21, 2018 11:56 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Molecular Shape
- Replies: 5
- Views: 437
Re: Molecular Shape
Yeah. Could help to make a table w the following columns (this is what I’m doing): # lone pairs | # bonding pairs | AXE formula | name | hybridization | drawing / description. Hope that helps.
- Wed Nov 21, 2018 11:53 am
- Forum: Sigma & Pi Bonds
- Topic: sigma and pi bonds
- Replies: 5
- Views: 553
Re: sigma and pi bonds
Signs bonds are single bonds, they’re stronger, formed end to end, able to rotate. Pi bonds are the other bond(s) of the multiple bond, weaker, more easily breakable, formed side to side, not able to rotate.
- Mon Nov 12, 2018 4:25 pm
- Forum: Resonance Structures
- Topic: Drawing resonance
- Replies: 17
- Views: 1775
Re: Drawing resonance
Yes draw all resonance structures and then double sided arrows between them indicating that there is resonance.
- Mon Nov 12, 2018 4:22 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: 3.53 6th edition
- Replies: 4
- Views: 1078
Re: 3.53 6th edition
Not quite sure what the molecules were but generally you find the formal charge of EACH element in the molecule (use the eq that the person said above) and then add them up to find the charge of the molecule. Each element should have the lowest formal charge possible (you can change it by moving the...
- Sun Nov 04, 2018 1:24 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: 7th edition 2A.11
- Replies: 1
- Views: 269
7th edition 2A.11
7th edition 2A.11: Which M^3+ ions (where M is a metal) are predicted to have the following ground state electron configurations: (a) [Ar]3d^6, (b) [Ar]3d^5. I thought the answer to a was Cu^3+, and that the answer for b was Ni^3+, but the answer key says that a is Co^3+ and b is Fe^3+. I really can...
- Fri Nov 02, 2018 10:37 am
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal charge purpose
- Replies: 40
- Views: 6845
Re: Formal charge purpose
What does a non-zero formal charge mean, besides that the molecule isn't in its most stable state? Do the numbers actually mean anything?
- Fri Nov 02, 2018 10:33 am
- Forum: Einstein Equation
- Topic: Calculating number of photons emitted
- Replies: 3
- Views: 2139
Re: Calculating number of photons emitted
E = hv is energy for one photon. You need to be given total energy of light source in order to find number of photons. Divide the total energy of light by the energy per photon to find number of photons. Remember number of photons determines intensity of light, not energy per photon.
- Fri Nov 02, 2018 10:27 am
- Forum: Administrative Questions and Class Announcements
- Topic: DOWNLOAD SESSION WORKSHEETS HERE - Sundays 4-6pm (Karen) [ENDORSED]
- Replies: 135
- Views: 37580
Re: DOWNLOAD SESSION WORKSHEETS HERE - Sundays 4-6pm (Karen) [ENDORSED]
Hi! Can you post the 4th worksheet key? And also do you have a worksheet with more Lewis Structures practice?
- Sat Oct 27, 2018 4:46 pm
- Forum: Trends in The Periodic Table
- Topic: 7th edition 1F.3
- Replies: 2
- Views: 345
7th edition 1F.3
How would you figure this out? "Place the following ions in order of increasing ionic radius: S^2-, Cl^-, P^3-." Its 7th edition 1F.3. Thanks!
- Fri Oct 26, 2018 12:24 am
- Forum: Photoelectric Effect
- Topic: Conditions that allow electron to be ejected from metal surface
- Replies: 12
- Views: 2067
Re: Conditions that allow electron to be ejected from metal surface
correct. the energy of the photon must be greater than or equal to the work function of the specific metal (the minimum amount of energy needed to eject an e-) in order to eject an e-. if the energy of the photon is less than the work function of the metal, no e- will be ejected. if the energy of th...
- Fri Oct 26, 2018 12:20 am
- Forum: Properties of Electrons
- Topic: Electron Energy
- Replies: 3
- Views: 459
Re: Electron Energy
I think you're asking two question here. The energy changes when the electron goes from 1s to 2p because the principle quantum number, which corresponds to size and energy, is changing from n = 1 to n = 2. For hydrogen, the orbitals in a certain energy level (ie: n = 1 or n = 2 or n = 3, etc) are de...
- Fri Oct 26, 2018 12:16 am
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Calculating Uncertainty in Momentum
- Replies: 3
- Views: 467
Re: Calculating Uncertainty in Momentum
use diameter for calculating uncertainty in position (delta x) because the diameter encompasses the whole area that the electron could be located. yes, your calculation for the uncertainty in position in that problem is correct. in that case you're finding a more specific area than just the diameter.
- Thu Oct 18, 2018 3:30 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Bohr condition explaining lines
- Replies: 2
- Views: 1700
Bohr condition explaining lines
How does the Bohr frequency condition explain the lines in the spectrum of an element? Thanks
- Thu Oct 18, 2018 3:28 pm
- Forum: Properties of Light
- Topic: Wave/particles
- Replies: 5
- Views: 430
Re: Wave/particles
One specific example regarding how light can be wave and particle is the intensity. In the wave model, the intensity is the amplitude squared, but in the particle model the intensity is the number of photons. Hope this helps.
- Thu Oct 18, 2018 3:25 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Atomic Spectra
- Replies: 4
- Views: 450
Re: Atomic Spectra
Since energy is directly proportional to frequency, its inversely related to wavelength (c = wavelength x freq and E = planks constant (h) x freq ==> derive (E = hc/wavelength) by plugging in for freq). There is a greater change in energy from n =5 to n = 1 than n = 4 to n = 2, so the transition fro...
- Thu Oct 18, 2018 3:19 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Atomic Spectroscopy vs Molecular Spectroscopy
- Replies: 2
- Views: 366
Atomic Spectroscopy vs Molecular Spectroscopy
Whats the difference between atomic spectroscopy and molecular spectroscopy? On Dr. Lavelle's syllabus it says "understand the difference bt electronic transitions in atomic orbitals (atomic spectroscopy) and electronic transitions in molecular orbitals (molecular spectroscopy)." What does...
- Tue Oct 09, 2018 9:22 pm
- Forum: Balancing Chemical Reactions
- Topic: 7th edition L.35
- Replies: 5
- Views: 651
Re: 7th edition L.35
There's a typo in the third equation. The reactant should be the same as the product of the second reaction: Fe3Br8. Hope this helps!
- Tue Oct 09, 2018 9:18 pm
- Forum: Empirical & Molecular Formulas
- Topic: Going from empirical to Molecular formula
- Replies: 14
- Views: 2048
Re: Going from empirical to Molecular formula
The factor that you get after dividing the molecular mass by the empirical mass should be an integer, or really close (I think if you can round from the hundredths place to an integer it's close enough). If you don't get an integer than re-check the empirical formula or empirical mass. It's really e...
- Tue Oct 09, 2018 9:12 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Question G13 (Sixth Edition)
- Replies: 3
- Views: 390
Re: Question G13 (Sixth Edition)
Hi! I just posted this same answer on another post but here goes: So first you have to isolate for Mf. Then you do (.2M * 1.0L)/(1+3L) to find the final molarity of the NH4NO3 solution, which is .05M. Once you have that, multiply by .1L (=100mL) to find how many moles of NH4NO3 for each plant, which...
- Tue Oct 09, 2018 9:10 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Homework Problem in Section G
- Replies: 3
- Views: 278
Re: Homework Problem in Section G
So first you have to isolate for Mf. Then you do (.2M * 1.0L)/(1+3L) to find the final molarity of the NH4NO3 solution, which is .05M. Once you have that, multiply by .1L (=100mL) to find how many moles of NH4NO3 for each plant, which is .005 mol NH4NO3. Then use mole ratios to find the moles of jus...
- Wed Oct 03, 2018 11:20 pm
- Forum: Limiting Reactant Calculations
- Topic: Combustion Analysis? [ENDORSED]
- Replies: 7
- Views: 374
Combustion Analysis? [ENDORSED]
Will combustion analysis be on the test? We haven't talked about it but it was in the limiting reactant section in the textbook (Fundamentals Section M3).
- Wed Oct 03, 2018 11:17 pm
- Forum: SI Units, Unit Conversions
- Topic: Week 2 homework
- Replies: 2
- Views: 246
Re: Week 2 homework
Since we're starting on Quantum World lectures on Friday the homework for Week 2 will be from that section. My TA said just to turn in the problems that you know how to do if you haven't gone over everything in lecture yet. Hope this helps!
- Wed Oct 03, 2018 11:12 pm
- Forum: SI Units, Unit Conversions
- Topic: Unit Notation
- Replies: 2
- Views: 261
Re: Unit Notation
It just makes it simpler to look at. The negative exponent and division sign mean the same thing but all of the /'s get confusing, so I prefer using the negative exponent method. It also helps with dimensional analysis bc the units are clearer.