Search found 30 matches
- Mon Jun 11, 2018 4:23 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Atom vs lone pair
- Replies: 3
- Views: 413
Re: Atom vs lone pair
Lone pairs have higher electron - electron repulsion and thus they take up more space than atoms, pushing the surrounding atoms closer together and lowing their bonding angle.
- Mon Jun 11, 2018 4:17 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: HW 17.33
- Replies: 6
- Views: 812
Re: HW 17.33
I think it could be monodentate or bidentate as well, it would depend on which would produce the most stable structure.
- Mon Jun 11, 2018 3:45 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Lone Pairs Affecting Bond Angles/Shape?
- Replies: 4
- Views: 814
Re: Lone Pairs Affecting Bond Angles/Shape?
Lone pairs reduce bonding angles because they take up more space, resulting from their higher electron-electron repulsion, but I'm not exactly sure what you mean by something that has more than one pair having a specific name.
- Sun Jun 03, 2018 2:13 pm
- Forum: Ionic & Covalent Bonds
- Topic: Help on 3.25 [ENDORSED]
- Replies: 3
- Views: 484
Re: Help on 3.25 [ENDORSED]
Keep in mind that the roman numerals indicate of the charge of the element. Ex: bismuth(III) has a +3 charge.
- Sun Jun 03, 2018 2:07 pm
- Forum: Dipole Moments
- Topic: 6.1 and 6.19 question
- Replies: 3
- Views: 588
Re: 6.1 and 6.19 question
No it has to do with the shape. Since CH3(CH2)3CH3 is linear, it has a greater surface area, and thus more contact points for london forces to occur. The more interactions there are the stronger they are as a unit, which translates to the higher the boiling point.
- Sun Jun 03, 2018 2:00 pm
- Forum: Lewis Structures
- Topic: Test Q.8 [ENDORSED]
- Replies: 7
- Views: 910
Re: Test Q.8 [ENDORSED]
Think of the bonds in a resonance structure with single and double bonds as a blend between the two. In reality, the molecule will not have discrete single and double bonds, rather all its bonds will be the same intermediate mix between single and double bonds. You could sort of think of it like a &...
- Sun May 27, 2018 10:28 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: structure SF4
- Replies: 2
- Views: 383
Re: structure SF4
The lone pair takes up space, so you could not arrange the fluorine atoms in a tetrahedral shape.
- Sun May 27, 2018 10:25 pm
- Forum: Resonance Structures
- Topic: Contributing to Resonance Structures
- Replies: 4
- Views: 643
Re: Contributing to Resonance Structures
Whatever structure has the lowest energy state(such as the most favorable formal charge) contributes the most to resonance structure; so if all that separates equally low energy states is the position of a double bond, then showing all the alternate double bond positions would be the correct thing t...
- Sun May 27, 2018 10:19 pm
- Forum: Dipole Moments
- Topic: dipole moments and polarization
- Replies: 3
- Views: 456
Re: dipole moments and polarization
In water the dipole moments are not linearly opposing each other, which is why they do not cancel each other out. For this reason the molecule is polar.
- Sun May 20, 2018 9:44 pm
- Forum: Octet Exceptions
- Topic: Expanded Octet
- Replies: 2
- Views: 463
Re: Expanded Octet
Are there any cases where all 10 extra are taken up?
- Sun May 20, 2018 9:36 pm
- Forum: Lewis Structures
- Topic: Friday's Lecture [ENDORSED]
- Replies: 4
- Views: 607
Re: Friday's Lecture [ENDORSED]
Test three only covers chapter 3.
- Sun May 20, 2018 9:35 pm
- Forum: Ionic & Covalent Bonds
- Topic: 3.25 c)
- Replies: 4
- Views: 656
Re: 3.25 c)
The cation of Hydrogen is just a proton, so there probably are not any electron shells associated with it.
- Sun May 13, 2018 12:43 pm
- Forum: Lewis Structures
- Topic: formal charge?
- Replies: 3
- Views: 2457
Re: formal charge?
Formal charge can be calculated using the formula: (# of valence electrons on an atom) - (non bonded electrons + number of bonds).
- Sun May 13, 2018 12:37 pm
- Forum: Properties of Electrons
- Topic: Electron Affinity
- Replies: 4
- Views: 757
Re: Electron Affinity
These trends have many of exceptions, however, so it is also important to take the element's electron configuration into consideration when determining how it would respond to additional electrons.
- Sun May 13, 2018 11:49 am
- Forum: Ionic & Covalent Bonds
- Topic: 3.33
- Replies: 5
- Views: 632
Re: 3.33
Also be mindful of exceptions, like oxygen, which has a lower ionization energy than nitrogen, yet is not in the center for the lewis dot of NO3.
- Sun May 06, 2018 11:23 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: test 2 #4
- Replies: 4
- Views: 601
Re: test 2 #4
I believe E=-hR/n^2 is only valid for hydrogen, yet this equation was not needed on the test.
- Sun May 06, 2018 11:14 am
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Everyday Objects and heisenberg's equation [ENDORSED]
- Replies: 2
- Views: 464
Re: Everyday Objects and heisenberg's equation [ENDORSED]
With large everyday objects we can measure momentum and position with great precision, so the resulting uncertainty is negligible.
- Sun May 06, 2018 11:08 am
- Forum: Photoelectric Effect
- Topic: 1.69
- Replies: 2
- Views: 411
Re: 1.69
In order to solve this problem first convert the 2.93 eV to J. Then, convert both given wavelengths into J using E=hv to see which one corresponds to an energy greater than the 2.93 eV. After you decide which laser has the higher E, subtract the work function from this value in order to find the ene...
- Sun Apr 29, 2018 11:31 am
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Nodal Planes [ENDORSED]
- Replies: 6
- Views: 825
Re: Nodal Planes [ENDORSED]
Nodal planes specify that there is 0 probability of finding an electron at that nodal plane, the don't really specify much about the way electrons are distributed in the areas that have a significant probability.
- Sun Apr 29, 2018 11:13 am
- Forum: Photoelectric Effect
- Topic: What is work function? [ENDORSED]
- Replies: 15
- Views: 5733
Re: What is work function? [ENDORSED]
The equation to solve for the work function is E(Photon)=Work Function(Threshold Energy) + E(Kinetic)
- Sun Apr 29, 2018 11:08 am
- Forum: *Shrodinger Equation
- Topic: Shrodinger Equation
- Replies: 7
- Views: 872
Re: Shrodinger Equation
I don't think we will have to directly apply the Shrodinger Equation to any problems in this course.
- Sun Apr 22, 2018 12:21 pm
- Forum: DeBroglie Equation
- Topic: HW 1.33
- Replies: 12
- Views: 1274
Re: HW 1.33
8.8nm would still be a part of the X-ray spectrum, I believe.
- Sun Apr 22, 2018 12:16 pm
- Forum: DeBroglie Equation
- Topic: DeBrogile Module
- Replies: 6
- Views: 559
Re: DeBrogile Module
SI unit for distance is the meter and for time is the second, so you did the correct thing by converting it.
- Wed Apr 18, 2018 1:07 pm
- Forum: DeBroglie Equation
- Topic: HW 1.33
- Replies: 12
- Views: 1274
Re: HW 1.33
You can use this given frequency to calculate the threshold energy using the equation, E = (h)(v). From there you should be able to use the work function to calculate the energy of the photon needed to displace an electron the given 3.6x10^3 km/s.
- Sat Apr 14, 2018 10:37 pm
- Forum: Empirical & Molecular Formulas
- Topic: Combustion Reaction [ENDORSED]
- Replies: 6
- Views: 664
Re: Combustion Reaction [ENDORSED]
I meant can you use a combustion reaction to find the empirical formula of a compound that does not contain oxygen? Or will oxygen always be present in the final empirical formula?
- Sat Apr 14, 2018 10:27 pm
- Forum: Empirical & Molecular Formulas
- Topic: Combustion Reaction [ENDORSED]
- Replies: 6
- Views: 664
Combustion Reaction [ENDORSED]
When using a combustion reaction to find the empirical formula of a compound, will oxygen always be one of the elements we are tying to solve for?
- Sat Apr 14, 2018 10:07 pm
- Forum: Properties of Light
- Topic: Quantized v. Discrete
- Replies: 5
- Views: 514
Re: Quantized v. Discrete
A discrete variable is something that has a defined set of possible values. A hydrogen atom is an example, as we can not have .33 or 1.7 hydrogen atoms. Instead, only discrete whole values (1 atom, 5 atoms, 456 atoms) are valid to quantify the variable.
- Sat Apr 14, 2018 8:21 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Balmer Series
- Replies: 2
- Views: 227
Re: Balmer Series
Yes, I believe the Balmer series falls within the visible region of approximately 400nm - 700nm.
- Sat Apr 14, 2018 8:08 pm
- Forum: Significant Figures
- Topic: Sig fifs in 750 [ENDORSED]
- Replies: 6
- Views: 1386
Re: Sig fifs in 750 [ENDORSED]
Yes, both of those would have two significant figures. Putting decimals less than one in scientific notation makes it very easy to tell which numbers are significant as only the digits that appear before the "x10" are.
- Sat Apr 14, 2018 7:41 pm
- Forum: Photoelectric Effect
- Topic: ENERGY PER MOLE OF PHOTONS [ENDORSED]
- Replies: 3
- Views: 389
Re: ENERGY PER MOLE OF PHOTONS [ENDORSED]
The units of Avogadro's number is "things" per mole, which is why when the energy of a photon is given per mole, we have to multiply by Avogadro's number to determine energy per photon.