Search found 55 matches
- Sun Dec 08, 2019 7:58 pm
- Forum: Hybridization
- Topic: Pi bond
- Replies: 10
- Views: 735
Re: Pi bond
Pi bonds have to be atomic orbitals,not hybrid orbitals
- Sun Dec 08, 2019 7:56 pm
- Forum: Hybridization
- Topic: 2sp2 and sp2
- Replies: 10
- Views: 799
Re: 2sp2 and sp2
For hybridization, the 2 is not needed, but it is if asking about specific orbitals
Re: Chelating
Any polydentate ligand is a chelating ligand
- Sun Dec 08, 2019 7:54 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal Charge
- Replies: 11
- Views: 793
Re: Formal Charge
Formal charge is valence minus number of lines and dots, and you can get a negative or a postiive answer when you do that
- Sun Dec 08, 2019 7:51 pm
- Forum: General Science Questions
- Topic: Polarizbity
- Replies: 2
- Views: 446
Re: Polarizbity
Fe3+ has more polarizing power because it is more positively charged and smaller.
- Sun Dec 01, 2019 6:12 pm
- Forum: Student Social/Study Group
- Topic: Study Strategies
- Replies: 6
- Views: 440
Re: Study Strategies
It sounds like you are doing fine in the class. I would say that reading over some of the textbook and attending the workshops are very helpful in reviewing and applying what we learned in lecture.
- Sun Dec 01, 2019 6:07 pm
- Forum: General Science Questions
- Topic: Final Review
- Replies: 3
- Views: 304
Final Review
Is there going to be a final review session held by the UAs like there was for the midterm?
- Sun Dec 01, 2019 6:05 pm
- Forum: Conjugate Acids & Bases
- Topic: Acids and Bases
- Replies: 3
- Views: 265
Acids and Bases
Can someone explain the difference between conjugate, Bronsted, and Lewis acids and bases?
- Sun Dec 01, 2019 6:00 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: pH calcuations
- Replies: 8
- Views: 423
pH calcuations
Are pH=-log(H+) and pH=-log(OH-) the only equations we need to know, regarding pH, for the final?
- Sun Dec 01, 2019 5:59 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Ligand
- Replies: 4
- Views: 328
Ligand
What exactly is chelation and what are some examples of chelating ligands?
- Sun Nov 24, 2019 10:34 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Hydrogen Bonding
- Replies: 13
- Views: 648
Re: Hydrogen Bonding
305376058 wrote:Typically, yes, because the hydrogen is attracted to atoms N, O, and F, that have stronger partial negative charges.
I would also add that the N O F atoms must have a lone pair for hydrogen to bond.
- Sun Nov 24, 2019 10:30 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: EDTA
- Replies: 1
- Views: 172
EDTA
What is the point of using EDTA^4- to remove metals from solutions?
- Sun Nov 24, 2019 10:24 pm
- Forum: Naming
- Topic: Di-, Tri-, Tetra- vs Bis-, Tris-, Tetrakis-
- Replies: 11
- Views: 910
Re: Di-, Tri-, Tetra- vs Bis-, Tris-, Tetrakis-
Bilal Pandit 3F wrote:They are used when the ligand has a prefix itself, so the ligand would have a di, tri, etc, so instead of saying didi, you would just say dis.
How do you know which is the ligand?
- Sun Nov 24, 2019 10:15 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond angles
- Replies: 7
- Views: 414
Bond angles
How do you determine the bond angles for a seesaw shaped molecule?
- Sun Nov 24, 2019 10:04 pm
- Forum: Biological Examples
- Topic: Cisplatin
- Replies: 8
- Views: 485
Cisplatin
Why cisplatin is used for chemotherapy and not transplatin?
- Sun Nov 17, 2019 12:58 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: dipole-dipole
- Replies: 3
- Views: 232
Re: dipole-dipole
The electronegativity difference is big between the N and the H and also the O and the H which creates dipoles.
- Sun Nov 17, 2019 12:57 am
- Forum: General Science Questions
- Topic: Time Management Tips in Test
- Replies: 5
- Views: 441
Re: Time Management Tips in Test
My iq drops as well, but i think just try to not think about the time and just try your best!
- Sun Nov 17, 2019 12:55 am
- Forum: General Science Questions
- Topic: Test 2 Review
- Replies: 8
- Views: 594
Re: Test 2 Review
I think vsepr and molecular shape is where we start for test 2, and intermolecular forces
- Sun Nov 17, 2019 12:54 am
- Forum: Dipole Moments
- Topic: Atom and Molecule Size
- Replies: 1
- Views: 161
Re: Atom and Molecule Size
If no other intermolecular forces are different between the two, larger ones should have stronger attractions because of the london forces.
- Sun Nov 17, 2019 12:53 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Axial and Equatorial
- Replies: 2
- Views: 242
Re: Axial and Equatorial
Equatorial ones are on the x-axis or horizontal plane like an equator and axial ones are the vertical ones,
- Sun Nov 17, 2019 12:52 am
- Forum: General Science Questions
- Topic: Midterm Review
- Replies: 2
- Views: 212
Re: Midterm Review
I am pretty sure you can go to your TA to review the test!
- Fri Nov 08, 2019 2:05 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ionization of Nitrogen vs Oxygen
- Replies: 11
- Views: 1527
Re: Ionization of Nitrogen vs Oxygen
Oxygen has a 4th electron which makes a pair in the orbital which has more electron repulsion due to that paired electron, giving it a lower ionization energy.
- Fri Nov 08, 2019 2:03 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: Hydrogen bonding specificity
- Replies: 3
- Views: 160
Re: Hydrogen bonding specificity
Because those have high electronegativity which makes a strong dipole when bonded to the H.
- Fri Nov 08, 2019 2:03 pm
- Forum: *Liquid Structure (Viscosity, Surface Tension, Liquid Crystals, Ionic Liquids)
- Topic: Polarizability and States
- Replies: 3
- Views: 538
Re: Polarizability and States
I dont think there is a relationship, I think larger atoms are generally more polarizable.
- Fri Nov 08, 2019 2:01 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Discussion-Week 9
- Replies: 3
- Views: 160
Re: Discussion-Week 9
There definitely wont be any discussion thursday or friday but not sure about tues-wed
- Fri Nov 08, 2019 2:00 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: Interaction potential energy equations
- Replies: 1
- Views: 131
Re: Interaction potential energy equations
I think it is talking more about attractive energy. So the more negative the potential energy is, the stronger the attractive force is.
- Fri Nov 08, 2019 1:59 pm
- Forum: Sigma & Pi Bonds
- Topic: Sigma & Pi Bonds
- Replies: 5
- Views: 224
Re: Sigma & Pi Bonds
Pi bonds are side by side overlap of p-orbitals, sigma bonds are other types of overlapping orbitals.
- Sat Nov 02, 2019 12:07 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ionic/Covalent
- Replies: 6
- Views: 178
Re: Ionic/Covalent
I think the idea is that bonds are not binary. For example, like gender, bonds lie on a spectrum of ionic and covalent character. Therefore, they are not always equally sharing (covalent) or completely giving up electrons (ionic), so they have some characteristics of both.
- Sat Nov 02, 2019 12:04 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Ionization Energy
- Replies: 3
- Views: 143
Re: Ionization Energy
The exceptions for ionization energy are the one mentioned with O and N and it also applies to the elements directly below, which are P and S.
- Sat Nov 02, 2019 12:01 pm
- Forum: Trends in The Periodic Table
- Topic: Noble Gases
- Replies: 10
- Views: 611
Re: Noble Gases
Yes, noble gases have ionization energies and electron affinities. Since noble gases are very very stable (inert/won't react), they do not want to gain or lose an electron. Therefore, they will have very high ionization energies and very low electron affinities.
- Sat Nov 02, 2019 11:59 am
- Forum: Octet Exceptions
- Topic: Expanded Octet
- Replies: 3
- Views: 166
Re: Expanded Octet
Any element from row 3 and beyond can have expanded octet because when n=3, l=0,1,2 which means elements in the third row have access to a 3d orbital, but none of the third row elements have any electrons in that orbital yet, so they can accommodate more electrons. Elements in the fourth row have a ...
- Sat Nov 02, 2019 11:56 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Titanium valence electrons
- Replies: 2
- Views: 238
Re: Titanium valence electrons
I don't think we count valence electrons for d-block elements but they can have multiple oxidation states.
- Sat Nov 02, 2019 11:53 am
- Forum: Bond Lengths & Energies
- Topic: Bonding
- Replies: 7
- Views: 410
Re: Bonding
The 3rd row and beyond can have expanded octet, more than 8 electrons. H, He, Li, Be will always have an incomplete octet. The 13th column or the Boron column can have an incomplete octet.
- Sat Nov 02, 2019 11:50 am
- Forum: Administrative Questions and Class Announcements
- Topic: DINO NUGGETS Review Session! Download Problems HERE [ENDORSED]
- Replies: 52
- Views: 6507
Re: DINO NUGGETS Review Session! Download Problems HERE [ENDORSED]
sbottomley3a wrote:How will the difficulty of these problems compare to the difficulty of the midterm?
At the review session, he said the problems just as hard or harder than midterm questions ideally.
- Wed Oct 23, 2019 4:55 pm
- Forum: Trends in The Periodic Table
- Topic: Shielding
- Replies: 8
- Views: 539
Re: Shielding
Since some people already responded to your question on what shield is, I'll just say how it affects ionization energy. Basically, you will see a trend of decreasing ionization energy down the periodic table and a trend of increasing ionization energy across the period.
- Wed Oct 23, 2019 4:46 pm
- Forum: Electronegativity
- Topic: Electronegativity values
- Replies: 3
- Views: 175
Electronegativity values
Are we expected to know how to calculate these values in order to find electronegativity differences?
- Wed Oct 23, 2019 4:37 pm
- Forum: Lewis Structures
- Topic: Exceptions
- Replies: 3
- Views: 71
Re: Exceptions
They only need 2 electrons to be satisfied, so if lithium loses an electron it will be stable.
- Wed Oct 23, 2019 4:34 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: electron configurations
- Replies: 2
- Views: 118
electron configurations
How can you tell if an atom is in its ground state or an excited state by looking at its electron configuration? For example, Li: [Ar] 1s^2 2p^1
- Wed Oct 23, 2019 4:19 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ionic Compounds
- Replies: 6
- Views: 220
Re: Ionic Compounds
In ionic compounds, the anions transfer electrons to cations, which are lacking, so that both atoms achieve a noble gas like configuration. As for covalent bonds, the electrons are simply shared, meaning that electrons are not given into the other atom unlike in ionic bonds.
- Sun Oct 20, 2019 10:11 pm
- Forum: Properties of Light
- Topic: What are the units of hertz
- Replies: 41
- Views: 1929
Re: What are the units of hertz
1 Hz = 1 cycle/second
- Sun Oct 20, 2019 9:55 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Test 1- Q5a
- Replies: 2
- Views: 198
Re: Test 1- Q5a
the equation you used was right, but you may have messed up when you plugged in the values. I did 10g/194.19g.mol^-1 divided by .240 L and got .215M.
- Sun Oct 20, 2019 9:48 pm
- Forum: Photoelectric Effect
- Topic: The Work Function
- Replies: 15
- Views: 967
Re: The Work Function
Arianna Perea 3H wrote:does the metal eject electron if the energy and work function are the same?
As long as the energy of the photon is greater or equal to the work function, the metal will eject the electron. Any excess energy is regarded as kinetic energy.
- Sun Oct 20, 2019 9:47 pm
- Forum: Photoelectric Effect
- Topic: The Work Function
- Replies: 15
- Views: 967
Re: The Work Function
Could someone explain to be how you use the work function to find kinetic energy of an electron and the energy needed to remove an electron. Specifically in the case of these two questions from the video module assessments. "Light hits a sodium metal surface and the velocity of the ejected ele...
- Sun Oct 20, 2019 9:41 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Uncertainty value in equation
- Replies: 9
- Views: 339
Re: Uncertainty value in equation
You would add it up, so the uncertainty value would be 6.
- Sun Oct 20, 2019 9:37 pm
- Forum: General Science Questions
- Topic: Quick clarification
- Replies: 4
- Views: 295
Re: Quick clarification
The number you are referring to is Planck's constant(h) which relates the energy in one photon of electromagnetic radiation to its frequency.
- Sun Oct 13, 2019 8:54 pm
- Forum: Einstein Equation
- Topic: Einstein's Equation
- Replies: 7
- Views: 273
Re: Einstein's Equation
The photoelectric experiment consisted of shining light onto a metal surface to measure the energy needed to remove electrons from different metals. Kinetic energy is equal to energy of the photon minus the the energy to remove the electron (work function/threshold energy). This equation illustrates...
- Sun Oct 13, 2019 8:47 pm
- Forum: Properties of Light
- Topic: Wavelength
- Replies: 4
- Views: 173
Re: Wavelength
You can just divide the speed of light by the given velocity using c=hv
- Sun Oct 13, 2019 8:39 pm
- Forum: Photoelectric Effect
- Topic: De Broglie's Equation
- Replies: 5
- Views: 237
Re: De Broglie's Equation
De Broglie's equations applies as long as the particle in question has p, momentum(mv), and has wavelike properties. Depending on the question, you can use the equation to find mass, velocity, or wavelength.
- Sun Oct 13, 2019 8:35 pm
- Forum: Properties of Electrons
- Topic: constructive vs destructive interference
- Replies: 3
- Views: 222
Re: constructive vs destructive interference
Diffraction results from constructive and destructive interference. Constructive waves are in phase, which means their crests and troughs line up with one another to result in a wave with a larger amplitude. Destructive waves are out of phase, so the resulting wave's amplitude is lower than the init...
- Sun Oct 13, 2019 8:28 pm
- Forum: Properties of Light
- Topic: hw problem 1A.7
- Replies: 3
- Views: 162
Re: hw problem 1A.7
The equation for the speed of light is c = frequency x wavelength. If you remember, c is a constant, 2.998 X 10^8 m/s.
- Fri Oct 04, 2019 6:34 pm
- Forum: Properties of Light
- Topic: unit change
- Replies: 4
- Views: 221
Re: unit change
Hertz is the SI unit for frequency, and it tells you cycles/second. When anything is denoted by ^-1, it puts the unit goes under 1. For example, s^-1 is 1/s, and g.mol^-1 is the equivalent of g/mol.
- Fri Oct 04, 2019 6:24 pm
- Forum: Empirical & Molecular Formulas
- Topic: Writing Empirical Formulas
- Replies: 8
- Views: 851
Re: Writing Empirical Formulas
I noticed that in the practice problems, you can just write the elements in the same order the mass percentage compositions or mass of the elements are shown.
- Fri Oct 04, 2019 6:17 pm
- Forum: Limiting Reactant Calculations
- Topic: Reviewing High School Chem Tips
- Replies: 10
- Views: 782
Re: Reviewing High School Chem Tips
If you can, try to look back at your old notes. If not, watching Khan Academy and other available videos is super helpful. Just make sure that afterwards you are able to apply your knowledge by practicing textbook problems, especially in sections where you find you are more unsure.
- Fri Oct 04, 2019 6:07 pm
- Forum: SI Units, Unit Conversions
- Topic: Sig figs
- Replies: 18
- Views: 603
Re: Sig figs
https://lavelle.chem.ucla.edu/wp-content/supporting-files/Chem14A/EVERYTHING_YOU_WANTED_TO_KNOW_ABOUT_SF.pdf This is the link on Lavelle's website that explains how sig figs work. There is no set number of decimal places or sig fig for the whole set; after reading over the pdf, use sig figs at the e...
- Fri Oct 04, 2019 6:00 pm
- Forum: SI Units, Unit Conversions
- Topic: SI
- Replies: 5
- Views: 222
Re: SI
Based on the lecture, base SI units we need to know are grams (mass), meters (length), and seconds (time). It's also helpful to note certain prefixes, such as: Giga (G), mega (M), kilo (k), centi (c), milli (m), micro, and nano (n), and the degree each indicates.