Search found 50 matches
- Sat Dec 07, 2019 12:44 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Line Structures
- Replies: 1
- Views: 207
Line Structures
When interpreting line structures, how do you determine how many hydrogen atoms are present?
- Tue Dec 03, 2019 9:04 pm
- Forum: Student Social/Study Group
- Topic: Paramagnetic and Diamagnetic
- Replies: 2
- Views: 299
Paramagnetic and Diamagnetic
For the Chem 14A final, should we know how to determine if a molecule or ion is paramagnetic or diamagnetic?
- Mon Dec 02, 2019 9:11 am
- Forum: Naming
- Topic: Coordination Compound: Cation or Anion
- Replies: 3
- Views: 326
Coordination Compound: Cation or Anion
If the complex ion (what is inside the brackets) is the cation, will it always be written first? And, vice versa if it is the anion?
- Mon Dec 02, 2019 9:08 am
- Forum: Naming
- Topic: Neutral Molecules
- Replies: 2
- Views: 231
Neutral Molecules
I have noticed that two common neutrally charged molecules within coordination compounds are H2O and NH3. Are there any other common neutrally charged molecules that I should familiarize myself with in regards to coordination compounds?
- Sat Nov 30, 2019 4:38 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Square-Planar Complex vs. Tetrahedral Complex
- Replies: 2
- Views: 248
Square-Planar Complex vs. Tetrahedral Complex
How do you know when a coordination compound with 4 ligands form a tetrahedral complex or a square-planar complex?
- Sat Nov 30, 2019 4:31 pm
- Forum: Naming
- Topic: Complex Ion: Anion vs. Cation
- Replies: 1
- Views: 158
Complex Ion: Anion vs. Cation
When naming a coordination compound, how does the complex ion being the anion or the cation affect the name?
- Fri Nov 29, 2019 2:41 pm
- Forum: Calculating the pH of Salt Solutions
- Topic: pH vs. pOH
- Replies: 17
- Views: 2265
pH vs. pOH
Can someone please explain the difference between pH and pOH?
- Fri Nov 29, 2019 2:37 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final Exam Location
- Replies: 11
- Views: 701
Final Exam Location
On MyUCLA, there are two rooms listed for my final exam location. How do I know which one is the true location I have to go to for my exam?
- Sat Nov 23, 2019 8:23 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: What is a chelate
- Replies: 2
- Views: 252
Re: What is a chelate
A chelate is a complex containing a ligand that forms a ring of atoms that includes the central metal atom. Chelating ligands can bind cations tightly. Bidentate, tridentate, and hexadentate are examples of chelates.
- Sat Nov 23, 2019 8:19 pm
- Forum: Biological Examples
- Topic: Biological Applications to Know
- Replies: 3
- Views: 301
Biological Applications to Know
Besides myoglobin and hemoglobin, what other biological applications of coordination compounds should we be aware of?
- Sat Nov 23, 2019 8:15 pm
- Forum: Hybridization
- Topic: Hybridization Notation
- Replies: 5
- Views: 371
Hybridization Notation
When writing out hybridization notation, does the d orbital come before s and p? For example, "dsp^3" instead of "sp^3d."
- Sat Nov 23, 2019 3:34 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Thanksgiving Break
- Replies: 4
- Views: 430
Thanksgiving Break
If my discussion is on Thursday (Thanksgiving Day), when would I turn in my Week 9 homework assignment?
- Fri Nov 15, 2019 9:04 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Polar vs Nonpolar Example
- Replies: 3
- Views: 315
Polar vs Nonpolar Example
In today's lecture, Professor Lavelle used cis-dichloroethene as an example of a polar molecule and trans-dichloroethene as an example of a nonpolar molecule. This made me very confused because they have the same structure (according to the powerpoint), but the arrows were in different areas. Can so...
- Fri Nov 15, 2019 8:55 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR Notation
- Replies: 5
- Views: 280
VSEPR Notation
Do the numbers accompanying the A, X, and E depend on electron pairs or individual electrons?
- Fri Nov 15, 2019 8:47 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: T Shape
- Replies: 7
- Views: 499
Re: T Shape
Just to be safe, I would familiarize myself with all of the VSEPR shapes.
- Fri Nov 15, 2019 8:45 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: test 2
- Replies: 13
- Views: 649
Re: test 2
We haven't gone over hybridization yet, so I would not expect it to be on the test. However, Professor Lavelle did say that he has one more page of information (which he will be going over in Monday's lecture) that will also be included on the test.
- Fri Nov 15, 2019 8:43 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: seesaw
- Replies: 9
- Views: 625
Re: seesaw
A molecule with a seesaw molecular geometry means that the molecule has four bonding pairs and one lone pair.
- Fri Nov 15, 2019 8:34 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Angles
- Replies: 6
- Views: 411
Bond Angles
How do you know when a bond angle is "slightly less" than the expected bond angle measure?
- Mon Nov 11, 2019 11:39 pm
- Forum: Lewis Structures
- Topic: Center of a Lewis Structure
- Replies: 7
- Views: 494
Re: Center of a Lewis Structure
Yes. Typically, the atom that is alone or has the lowest quantity in the formula is at the center of the Lewis structure.
- Mon Nov 11, 2019 11:36 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: Induced Dipole/ Induced Dipole
- Replies: 4
- Views: 266
Re: Induced Dipole/ Induced Dipole
Also, note that dispersion forces, induced-dipole-induced dipole forces, London forces, and Van der Waals forces are all the same.
- Mon Nov 11, 2019 2:23 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3003024
Re: Post All Chemistry Jokes Here
Why does a hamburger yield lower energy than a steak?
Because it's in the ground state.
Because it's in the ground state.
- Mon Nov 11, 2019 2:22 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3003024
Re: Post All Chemistry Jokes Here
Why did the white bear dissolve in water?
Because it was a polar bear.
Because it was a polar bear.
- Mon Nov 11, 2019 2:21 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3003024
Re: Post All Chemistry Jokes Here
Laughing Gas: He He He
- Mon Nov 11, 2019 2:16 pm
- Forum: Dipole Moments
- Topic: Ep Meaning
- Replies: 4
- Views: 464
Ep Meaning
Does "Ep" stand for potential energy? Or something else?
- Mon Nov 11, 2019 2:14 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3003024
Re: Post All Chemistry Jokes Here
I told a chemistry joke...
there was no reaction.
there was no reaction.
- Fri Nov 01, 2019 3:49 pm
- Forum: Dipole Moments
- Topic: Dipole Arrow
- Replies: 3
- Views: 203
Dipole Arrow
Does the arrow that represents the dipole always point toward the negative charge?
- Fri Nov 01, 2019 3:48 pm
- Forum: Dipole Moments
- Topic: Solving for the Dipole Moment
- Replies: 1
- Views: 119
Solving for the Dipole Moment
Can someone give me an example of solving for a dipole moment using numerical values? Is the charge (q) used in the dipole moment formula determined by their group on the periodic table?
- Fri Nov 01, 2019 3:43 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Distorted Electrons
- Replies: 4
- Views: 263
Distorted Electrons
Highly distorted electrons are described as being highly polarizable. But, how do you determine if an electron is a highly distorted electron?
- Fri Nov 01, 2019 3:39 pm
- Forum: Electronegativity
- Topic: Electronegativity Correlations
- Replies: 3
- Views: 169
Electronegativity Correlations
If ionization energy and electron affinity are high, then an atom will have high electronegativity. Does this mean ionization energy and electron affinity positively correlate with electronegativity?
- Fri Nov 01, 2019 3:28 pm
- Forum: Dipole Moments
- Topic: Week 6
- Replies: 1
- Views: 117
Week 6
Even though we have our midterm next week, will we still have five textbook problems and five chemistry community posts due?
- Fri Oct 25, 2019 8:03 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Resonance Hybrid
- Replies: 2
- Views: 75
Resonance Hybrid
What is a resonance hybrid? How do you determine how to draw a resonance hybrid?
- Fri Oct 25, 2019 8:02 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Formal Charge
- Replies: 3
- Views: 179
Formal Charge
When drawing Lewis structures, should I always aim for a 0 formal charge? Is this possible for all Lewis structures?
- Fri Oct 25, 2019 8:02 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Drawing Lewis Structures
- Replies: 5
- Views: 293
Drawing Lewis Structures
What are the exceptions in drawing Lewis structures?
- Fri Oct 25, 2019 8:02 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configuration Chart
- Replies: 2
- Views: 103
Electron Configuration Chart
Can someone please explain why the electron configuration chart shortcut is inaccurate? If I use it, how must I change my answer to be correct?
- Fri Oct 25, 2019 8:00 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Effective Nuclear Charge
- Replies: 2
- Views: 93
Effective Nuclear Charge
Can someone define an effective nuclear charge? What makes it an effective nuclear charge?
- Fri Oct 18, 2019 8:51 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Two Exceptions
- Replies: 2
- Views: 67
Two Exceptions
In today's lecture, Professor Lavelle's PowerPoint noted two exceptions that we need to know when determining atomic states/orbitals. Under "need to know two exceptions," the slide said "half full d^5 and full d^10 subshell have lower energy." Did I misunderstand what the two exc...
- Fri Oct 18, 2019 8:45 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Orbital Order
- Replies: 2
- Views: 122
Orbital Order
In today's lecture, Professor Lavelle brought up how 3d comes before 4s, contrary to what most of us learned in high school. Can someone explain why this is the case?
- Thu Oct 17, 2019 7:18 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Drawing Orbitals
- Replies: 5
- Views: 258
Drawing Orbitals
Will Professor Lavelle ever ask us to draw out orbitals and their corresponding planes for future tests?
- Thu Oct 17, 2019 7:14 pm
- Forum: Photoelectric Effect
- Topic: Wave Properties vs. Particle Properties
- Replies: 3
- Views: 185
Wave Properties vs. Particle Properties
Can someone please explain why particle properties stop electrons from being ejected when light intensity increases. Thank you!
- Wed Oct 16, 2019 3:46 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Magnetic Quantum Number
- Replies: 3
- Views: 120
Magnetic Quantum Number
So, I understand how allowed values are determined for the magnetic quantum number. However, I am confused about how you determine the base (x, y, or z) of the orbital. In today's lecture, Professor Lavelle's example gave n=2, l=1, and m-base l=-1. The answer was that the electron was in a 2p-base x...
- Sat Oct 12, 2019 2:59 pm
- Forum: DeBroglie Equation
- Topic: De Broglie equation
- Replies: 5
- Views: 160
Re: De Broglie equation
According to SI units, mass is in kg. Nevertheless, always make sure you keep your units consistent while doing the math, especially when you have to deal with kg vs. g. Then, convert into the desired units at the end.
- Sat Oct 12, 2019 2:53 pm
- Forum: Properties of Light
- Topic: Diffraction and Water
- Replies: 4
- Views: 168
Re: Diffraction and Water
The diffraction patterns that are produced by electrons are similar to those of water waves when they enter two holes in a barrier to create separate wave fronts that combine and interact with each other. These waves can be formed from constructive interference (waves in phase) and destructive inter...
- Sat Oct 12, 2019 2:44 pm
- Forum: Properties of Light
- Topic: Light Intensity
- Replies: 6
- Views: 169
Light Intensity
Just to clarify, increasing light intensity increases the number of photons. And, if, and only if, the energy per photon is greater/equal to the energy needed to remove an electron, then increasing light intensity results in more ejected electrons. However, one cannot assume that electrons are being...
- Fri Oct 11, 2019 8:52 pm
- Forum: Student Social/Study Group
- Topic: Chemistry News
- Replies: 135
- Views: 163740
Re: Chemistry News
https://phys.org/news/2019-10-approach- ... cular.html
For everyone in Lavelle's Chem 14A lecture going over The Quantum World.
For everyone in Lavelle's Chem 14A lecture going over The Quantum World.
- Fri Oct 11, 2019 8:43 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Advice from a Medical Student [ENDORSED]
- Replies: 297
- Views: 382783
Re: Advice from a Medical Student [ENDORSED]
Thank you so much for sharing your bits of wisdom with us! I will definitely reach out to you if I come across obstacles this quarter and the next.
While you were at UCLA, did you overlap biology and chemistry? If so, what was that like? Any advice for balancing and keeping up with both?
While you were at UCLA, did you overlap biology and chemistry? If so, what was that like? Any advice for balancing and keeping up with both?
- Tue Oct 01, 2019 6:03 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test #1
- Replies: 3
- Views: 231
Test #1
Hi all,
For our first test, will it mostly consist of math-centered problems or will it also include vocabulary-related questions?
Thank you!
For our first test, will it mostly consist of math-centered problems or will it also include vocabulary-related questions?
Thank you!
- Tue Oct 01, 2019 5:54 pm
- Forum: Empirical & Molecular Formulas
- Topic: Homework Question F.23
- Replies: 2
- Views: 112
Re: Homework Question F.23
How far off were your calculations? If they were close enough and were able to get you to the correct answer, then I think you're doing great!
- Tue Oct 01, 2019 5:49 pm
- Forum: Empirical & Molecular Formulas
- Topic: Compound Formulas
- Replies: 2
- Views: 108
Compound Formulas
Are there any compound formulas that we should know by heart going into this course, especially once we get to writing out chemical equations ourselves?
- Tue Oct 01, 2019 5:38 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: HW G 19 *b
- Replies: 2
- Views: 129
Re: HW G 19 *b
To solve problem G 19 Part B, I calculated the number of moles of HCl I would get from 25 mL of 0.366 M HCl. This would equal 9.15x10^-3 mol HCl. Then, take that answer and divide it by 125 mL to solve for the molarity of the diluted solution. The answer you get is 0.073.
- Tue Oct 01, 2019 3:42 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: G.25 Dilution
- Replies: 4
- Views: 195
G.25 Dilution
Hi all,
I am currently working on problem G.25. If you dilute 10. mL of a solution and double the volume 90 times, would you simply multiply 10. mL by 90 and cancel out the mL/L with the molar concentration of the substance to find the number of molecules (using Avogadro's number)?
Thank you!
I am currently working on problem G.25. If you dilute 10. mL of a solution and double the volume 90 times, would you simply multiply 10. mL by 90 and cancel out the mL/L with the molar concentration of the substance to find the number of molecules (using Avogadro's number)?
Thank you!