Search found 50 matches

by ngarcia
Sat Dec 07, 2019 12:44 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Line Structures
Replies: 1
Views: 42

Line Structures

When interpreting line structures, how do you determine how many hydrogen atoms are present?
by ngarcia
Tue Dec 03, 2019 9:04 pm
Forum: Student Social/Study Group
Topic: Paramagnetic and Diamagnetic
Replies: 2
Views: 138

Paramagnetic and Diamagnetic

For the Chem 14A final, should we know how to determine if a molecule or ion is paramagnetic or diamagnetic?
by ngarcia
Mon Dec 02, 2019 9:11 am
Forum: Naming
Topic: Coordination Compound: Cation or Anion
Replies: 3
Views: 45

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?
by ngarcia
Mon Dec 02, 2019 9:08 am
Forum: Naming
Topic: Neutral Molecules
Replies: 2
Views: 38

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?
by ngarcia
Sat Nov 30, 2019 4:38 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Square-Planar Complex vs. Tetrahedral Complex
Replies: 2
Views: 38

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?
by ngarcia
Sat Nov 30, 2019 4:31 pm
Forum: Naming
Topic: Complex Ion: Anion vs. Cation
Replies: 1
Views: 28

Complex Ion: Anion vs. Cation

When naming a coordination compound, how does the complex ion being the anion or the cation affect the name?
by ngarcia
Fri Nov 29, 2019 2:41 pm
Forum: Calculating the pH of Salt Solutions
Topic: pH vs. pOH
Replies: 17
Views: 321

pH vs. pOH

Can someone please explain the difference between pH and pOH?
by ngarcia
Fri Nov 29, 2019 2:37 pm
Forum: Administrative Questions and Class Announcements
Topic: Final Exam Location
Replies: 11
Views: 159

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?
by ngarcia
Sat Nov 23, 2019 8:23 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: What is a chelate
Replies: 2
Views: 33

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.
by ngarcia
Sat Nov 23, 2019 8:19 pm
Forum: Biological Examples
Topic: Biological Applications to Know
Replies: 3
Views: 76

Biological Applications to Know

Besides myoglobin and hemoglobin, what other biological applications of coordination compounds should we be aware of?
by ngarcia
Sat Nov 23, 2019 8:15 pm
Forum: Hybridization
Topic: Hybridization Notation
Replies: 5
Views: 52

Hybridization Notation

When writing out hybridization notation, does the d orbital come before s and p? For example, "dsp^3" instead of "sp^3d."
by ngarcia
Sat Nov 23, 2019 3:34 pm
Forum: Administrative Questions and Class Announcements
Topic: Thanksgiving Break
Replies: 4
Views: 92

Thanksgiving Break

If my discussion is on Thursday (Thanksgiving Day), when would I turn in my Week 9 homework assignment?
by ngarcia
Fri Nov 15, 2019 9:04 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polar vs Nonpolar Example
Replies: 3
Views: 52

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...
by ngarcia
Fri Nov 15, 2019 8:55 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR Notation
Replies: 5
Views: 58

VSEPR Notation

Do the numbers accompanying the A, X, and E depend on electron pairs or individual electrons?
by ngarcia
Fri Nov 15, 2019 8:47 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: T Shape
Replies: 7
Views: 84

Re: T Shape

Just to be safe, I would familiarize myself with all of the VSEPR shapes.
by ngarcia
Fri Nov 15, 2019 8:45 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: test 2
Replies: 13
Views: 133

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.
by ngarcia
Fri Nov 15, 2019 8:43 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: seesaw
Replies: 9
Views: 114

Re: seesaw

A molecule with a seesaw molecular geometry means that the molecule has four bonding pairs and one lone pair.
by ngarcia
Fri Nov 15, 2019 8:34 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 6
Views: 60

Bond Angles

How do you know when a bond angle is "slightly less" than the expected bond angle measure?
by ngarcia
Mon Nov 11, 2019 11:39 pm
Forum: Lewis Structures
Topic: Center of a Lewis Structure
Replies: 7
Views: 89

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.
by ngarcia
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: 36

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.
by ngarcia
Mon Nov 11, 2019 2:23 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8015
Views: 1401606

Re: Post All Chemistry Jokes Here

Why does a hamburger yield lower energy than a steak?




Because it's in the ground state.
by ngarcia
Mon Nov 11, 2019 2:22 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8015
Views: 1401606

Re: Post All Chemistry Jokes Here

Why did the white bear dissolve in water?




Because it was a polar bear.
by ngarcia
Mon Nov 11, 2019 2:21 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8015
Views: 1401606

Re: Post All Chemistry Jokes Here

Laughing Gas: He He He
by ngarcia
Mon Nov 11, 2019 2:16 pm
Forum: Dipole Moments
Topic: Ep Meaning
Replies: 4
Views: 55

Ep Meaning

Does "Ep" stand for potential energy? Or something else?
by ngarcia
Mon Nov 11, 2019 2:14 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8015
Views: 1401606

Re: Post All Chemistry Jokes Here

I told a chemistry joke...




there was no reaction.
by ngarcia
Fri Nov 01, 2019 3:49 pm
Forum: Dipole Moments
Topic: Dipole Arrow
Replies: 3
Views: 32

Dipole Arrow

Does the arrow that represents the dipole always point toward the negative charge?
by ngarcia
Fri Nov 01, 2019 3:48 pm
Forum: Dipole Moments
Topic: Solving for the Dipole Moment
Replies: 1
Views: 27

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?
by ngarcia
Fri Nov 01, 2019 3:43 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Distorted Electrons
Replies: 4
Views: 101

Distorted Electrons

Highly distorted electrons are described as being highly polarizable. But, how do you determine if an electron is a highly distorted electron?
by ngarcia
Fri Nov 01, 2019 3:39 pm
Forum: Electronegativity
Topic: Electronegativity Correlations
Replies: 3
Views: 62

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?
by ngarcia
Fri Nov 01, 2019 3:28 pm
Forum: Dipole Moments
Topic: Week 6
Replies: 1
Views: 32

Week 6

Even though we have our midterm next week, will we still have five textbook problems and five chemistry community posts due?
by ngarcia
Fri Oct 25, 2019 8:03 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Resonance Hybrid
Replies: 2
Views: 32

Resonance Hybrid

What is a resonance hybrid? How do you determine how to draw a resonance hybrid?
by ngarcia
Fri Oct 25, 2019 8:02 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Formal Charge
Replies: 3
Views: 40

Formal Charge

When drawing Lewis structures, should I always aim for a 0 formal charge? Is this possible for all Lewis structures?
by ngarcia
Fri Oct 25, 2019 8:02 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Drawing Lewis Structures
Replies: 5
Views: 92

Drawing Lewis Structures

What are the exceptions in drawing Lewis structures?
by ngarcia
Fri Oct 25, 2019 8:02 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration Chart
Replies: 2
Views: 37

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?
by ngarcia
Fri Oct 25, 2019 8:00 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Effective Nuclear Charge
Replies: 2
Views: 35

Effective Nuclear Charge

Can someone define an effective nuclear charge? What makes it an effective nuclear charge?
by ngarcia
Fri Oct 18, 2019 8:51 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Two Exceptions
Replies: 2
Views: 35

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...
by ngarcia
Fri Oct 18, 2019 8:45 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Orbital Order
Replies: 2
Views: 55

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?
by ngarcia
Thu Oct 17, 2019 7:18 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Drawing Orbitals
Replies: 5
Views: 69

Drawing Orbitals

Will Professor Lavelle ever ask us to draw out orbitals and their corresponding planes for future tests?
by ngarcia
Thu Oct 17, 2019 7:14 pm
Forum: Photoelectric Effect
Topic: Wave Properties vs. Particle Properties
Replies: 3
Views: 56

Wave Properties vs. Particle Properties

Can someone please explain why particle properties stop electrons from being ejected when light intensity increases. Thank you!
by ngarcia
Wed Oct 16, 2019 3:46 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Magnetic Quantum Number
Replies: 3
Views: 33

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...
by ngarcia
Sat Oct 12, 2019 2:59 pm
Forum: DeBroglie Equation
Topic: De Broglie equation
Replies: 5
Views: 42

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.
by ngarcia
Sat Oct 12, 2019 2:53 pm
Forum: Properties of Light
Topic: Diffraction and Water
Replies: 4
Views: 52

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...
by ngarcia
Sat Oct 12, 2019 2:44 pm
Forum: Properties of Light
Topic: Light Intensity
Replies: 6
Views: 50

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...
by ngarcia
Fri Oct 11, 2019 8:52 pm
Forum: Student Social/Study Group
Topic: Chemistry News
Replies: 69
Views: 49505

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.
by ngarcia
Fri Oct 11, 2019 8:43 pm
Forum: Administrative Questions and Class Announcements
Topic: Advice from a Medical Student [ENDORSED]
Replies: 212
Views: 114977

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?
by ngarcia
Tue Oct 01, 2019 6:03 pm
Forum: Administrative Questions and Class Announcements
Topic: Test #1
Replies: 3
Views: 114

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!
by ngarcia
Tue Oct 01, 2019 5:54 pm
Forum: Empirical & Molecular Formulas
Topic: Homework Question F.23
Replies: 2
Views: 58

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!
by ngarcia
Tue Oct 01, 2019 5:49 pm
Forum: Empirical & Molecular Formulas
Topic: Compound Formulas
Replies: 2
Views: 62

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?
by ngarcia
Tue Oct 01, 2019 5:38 pm
Forum: Molarity, Solutions, Dilutions
Topic: HW G 19 *b
Replies: 2
Views: 44

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.
by ngarcia
Tue Oct 01, 2019 3:42 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: G.25 Dilution
Replies: 4
Views: 100

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!

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