Search found 24 matches
- Wed Jun 13, 2018 10:49 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3919246
Re: Post All Chemistry Jokes Here
Remember, all CATions are PAWsitive! XD
- Wed Jun 13, 2018 10:47 pm
- Forum: Empirical & Molecular Formulas
- Topic: Midterm Q3
- Replies: 3
- Views: 606
Re: Midterm Q3
This problem is a combustion problem so we know that one of the reactants is O2, and given the products of CO2, H2O, and N, we know that the oxygen in the products comes from O2. This would mean that C,H, and N make up nicotine. Also I believe during that midterm he told us it was CHN
- Wed Jun 13, 2018 10:37 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Oxidation Number
- Replies: 5
- Views: 917
Re: Oxidation Number
yazminedesan1F wrote:How do you find the oxidation number of a metal?
Metal ion + (number of ligands bound * charge of ligand) = overall charge of coordination compound. Hope this helps!
- Wed Jun 13, 2018 10:31 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VESPER Theory and Bond types
- Replies: 3
- Views: 705
Re: VESPER Theory and Bond types
The first bond in a double bond is a sigma and the second is a pi, which one is which is arbitrary. In a triple bond, there would be one sigma bond and two pi bonds.
- Wed Jun 13, 2018 10:20 pm
- Forum: Lewis Structures
- Topic: Coulomb's law
- Replies: 1
- Views: 338
Re: Coulomb's law
I think that for the final, we should be familiar with coloumb's law but I feel that a question solely on coulomb's law would be unlikely.
- Wed Jun 13, 2018 9:46 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Test 1, question 1 part B
- Replies: 1
- Views: 379
Re: Test 1, question 1 part B
In order to find the concentrations of Na ions in the final solutions, you must first find the concentration of the Na ions in the first solution. Using the Molecular formula of (Na2CO3), you know that the 0.0377 concentration of sodium bicarbonate must be doubled since there are two Na for every on...
- Wed Jun 13, 2018 9:31 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: ligands?
- Replies: 3
- Views: 676
Re: ligands?
I don't think we will be required to memorize ligands, so just know that a ligand is any atom or molecule that binds to another atoms.
- Wed Jun 13, 2018 9:29 pm
- Forum: Lewis Structures
- Topic: lewis structure
- Replies: 10
- Views: 1084
Re: lewis structure
in drawing a lewis structure, typically the least electronegative atom is the central atom
- Mon Jun 11, 2018 11:25 pm
- Forum: Hybridization
- Topic: How to figure out hybridization
- Replies: 5
- Views: 1252
Re: How to figure out hybridization
Does a lone pair count as one region of electron density? or do you count both electrons each as a region of density?
- Sun Jun 03, 2018 11:39 pm
- Forum: Ionic & Covalent Bonds
- Topic: Polarizability
- Replies: 7
- Views: 907
Re: Polarizability
the size of the electron cloud is determined by the energy of the atom's electrons, I believe. A few factors influence polarizability. The greater the amount of electrons, the less control the nuclear charge has on charge distribution, thus the increased polarizability of the atom. Additionally, th...
- Sun Jun 03, 2018 11:30 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Significance of Coordination Number?
- Replies: 7
- Views: 2598
Re: Significance of Coordination Number?
Amir Akhavan 1E wrote:I think it is important in naming the molecule and knowing its geometric shape. It could also be a question he may ask on the exam.
How would this be tested on the exam? Would it apply to the naming of the shape or the compound itself?
- Sun Jun 03, 2018 11:21 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Molecular Shape
- Replies: 6
- Views: 783
Re: Molecular Shape
Miya Lopez 1L wrote:But if you have more lone pairs, they would push the other bonds/molecules even further away from them correct? Thank you:)
Yes, additionally, I believe that the force that a lone pair exerts on bonds would be greater than the force a bond has on another bond.
- Fri May 25, 2018 11:08 am
- Forum: Octet Exceptions
- Topic: 3.61
- Replies: 4
- Views: 4700
Re: 3.61
There is a general rule when constructing lewis structures: any left over electrons usually are put on the central atom. Additionally, notice that Iodine has an expanded octet and can therefore accept those lone pairs.
- Sun May 20, 2018 8:32 pm
- Forum: Lewis Structures
- Topic: Different ways to write the lewis structure?
- Replies: 6
- Views: 854
Re: Different ways to write the lewis structure?
I believe that these two structures are essentially the same things because, as you said, they have equal numbers of bonds and electrons. Also, remember that resonance structures show the possible combinations of where electrons may be in the electron “cloud” so in actuality the electrons move aroun...
- Sat May 19, 2018 11:42 am
- Forum: Ionic & Covalent Bonds
- Topic: radicals [ENDORSED]
- Replies: 9
- Views: 1181
Re: radicals [ENDORSED]
does an atom have to give up or take an electron in order for it to be a radical? or if the valence shell has an odd number of electrons is it already considered a radical?
- Sat May 19, 2018 11:37 am
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Dipole-Induced Dipole Interactions in Solution [ENDORSED]
- Replies: 1
- Views: 474
Dipole-Induced Dipole Interactions in Solution [ENDORSED]
Do dipole-induced dipole interactions still occur in aqueous solution? For the example given in lecture on friday, Prof. Lavelle said that HCl would induce a dipole force in N2. Would this still be the case if HCl disassociated into H+ and Cl- in solution?
- Sun May 13, 2018 4:59 pm
- Forum: Resonance Structures
- Topic: Bonds or Lone Pairs more important?
- Replies: 7
- Views: 1127
Bonds or Lone Pairs more important?
When constructing a resonance structure, is it more common to add double bonds between atoms or lone pairs to the central atom to balance out the number of valence electrons?
- Sun May 13, 2018 4:41 pm
- Forum: Lewis Structures
- Topic: Expanded Octet
- Replies: 2
- Views: 656
Re: Expanded Octet
I don't think that they will always have more than 8 electrons because it depends on the total count of the valence electrons in the molecule. For example, when sodium and chlorine form NaCl, Cl does not have more than 8 electrons in its valence shell. The expanded octet rule does not mean that they...
- Sun May 13, 2018 4:36 pm
- Forum: Lewis Structures
- Topic: monatomic ion
- Replies: 2
- Views: 374
Re: monatomic ion
In context of this question, the monoatomic ion in part a would be both magnesium and arsenic. What the question refers to what it says "expected charges" is to balance the molecular formula so that the charges balance out between each monoatomic ion.
- Sun May 06, 2018 11:03 pm
- Forum: Sigma & Pi Bonds
- Topic: Hybrid orbitals
- Replies: 4
- Views: 619
Re: Hybrid orbitals
Basically, orbitals hybridize because hybridization allows for the molecule to be in its lowest possible energy state (or most stable state). The shape of hybridized orbitals depends on how many electrons are present how much energy they have
- Wed May 02, 2018 7:49 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configuration of Scandium
- Replies: 4
- Views: 829
Electron Configuration of Scandium
So in lecture on Wednesday, Prof. Lavelle used Scandium as an example to write out the electron configuration. His answer was Sc: [Ar]3d^1 4s^2. However, when I use the Aufbau principle, I get Sc: [Ar]4s^2 3d^1
Is the 3d orbital always going to be a higher energy level than 4s?
Is the 3d orbital always going to be a higher energy level than 4s?
- Sun Apr 22, 2018 7:21 pm
- Forum: Photoelectric Effect
- Topic: Photoelectric Effect
- Replies: 12
- Views: 1147
Re: Photoelectric Effect
Yes, in order for a photon to be emitted, the energy of the incoming photon must be equal to or greater than the threshold energy (the minimum energy it takes to eject one electron). Any "excess" energy is considered the kinetic energy of the ejected electron.
- Sun Apr 22, 2018 7:15 pm
- Forum: Properties of Light
- Topic: still don't uderrsatnd what a photon is [ENDORSED]
- Replies: 20
- Views: 1459
Re: still don't uderrsatnd what a photon is [ENDORSED]
Would it be wrong to say that a photon is the smallest quantum of light, like how one water molecule is the smallest quantum of water?
- Thu Apr 19, 2018 8:09 pm
- Forum: Photoelectric Effect
- Topic: 1.9
- Replies: 6
- Views: 502
Re: 1.9
The second value in the table is given as Energy equals 3.3x10^-19 J. I divided by Planck's constant using the equation E=hv and the result was 4.980x10^14. Is it unusual to have a wavelength that long?