## Search found 34 matches

Sun Dec 09, 2018 3:07 am
Forum: Lewis Acids & Bases
Topic: Al as a Lewis Acid
Replies: 2
Views: 320

### Re: Al as a Lewis Acid

Sun Dec 09, 2018 3:03 am
Forum: Student Social/Study Group
Topic: Chemistry News
Replies: 76
Views: 49807

### Re: Chemistry News

Hilda Sauceda 3C wrote:does anyone know is there is gonna be a study guide?

There will never be a studyguide, but at least Lavelle has many resources we can use like Chem community!
Sun Dec 09, 2018 3:00 am
Forum: General Science Questions
Topic: Can We Take The Final In Pencil?
Replies: 14
Views: 811

### Re: Can We Take The Final In Pencil?

I also hate writing in pen, but i usually do problems that have more change of being erased (lewis dot structures) in pencil first, then writing over it in pen once im sure about my answer.
Sun Dec 09, 2018 2:58 am
Forum: Student Social/Study Group
Topic: Bronsted Bases
Replies: 2
Views: 424

### Re: Bronsted Bases

Thank you!!
Sun Dec 09, 2018 2:56 am
Forum: Administrative Questions and Class Announcements
Topic: Advice from a Medical Student [ENDORSED]
Replies: 221
Views: 115702

### Re: Advice from a Medical Student[ENDORSED]

Sun Dec 09, 2018 2:54 am
Forum: Photoelectric Effect
Topic: Finding frequency
Replies: 2
Views: 2129

### Re: Finding frequency

Since we are given the wavelength of an electron, you must use the de Broglie equation, and in this case we would use it to find the velocity of the electron. (wavelength of particle = plancks constant / momentum (mass x velocity)). Since we know all values except for velocity, we can find it. Once ...
Sun Dec 09, 2018 2:47 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Polydentate
Replies: 3
Views: 202

### Re: Polydentate

Just like these posts have said, a polydentate has more than one ligand bounded to it (transition metal). Therefore, a monodentate is when the metal just has one. Keep in mind that polydentates will forma chelate, which is a ring structure in the molecule.
Fri Dec 07, 2018 1:55 am
Forum: *Crystal Field Theory
Topic: Crystal Field Theory
Replies: 5
Views: 930

### Re: Crystal Field Theory

To what extent do we need to know the Crystal Field Theory for 14A?
Fri Dec 07, 2018 1:54 am
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8199
Views: 1430058

### Re: Post All Chemistry Jokes Here

Q: If H-two-O is the formula for water, what is the formula for ice?
A: H-two-O-CUBED
Fri Dec 07, 2018 1:52 am
Forum: Identifying Acidic & Basic Salts
Topic: HW 12.17
Replies: 2
Views: 162

### Re: HW 12.17

The previous post perfectly explains this. The answers are therefore basic, acidic, amphoteric, and amphoteric in that order.
Fri Dec 07, 2018 1:49 am
Forum: Biological Examples
Topic: Cisplatin Example
Replies: 5
Views: 293

### Re: Cisplatin Example

Thank you for your help everyone!
Fri Dec 07, 2018 1:48 am
Forum: *Stereochemistry
Topic: What's a stereocenter?
Replies: 5
Views: 1215

### Re: What's a stereocenter?

Do we need to know this for the final?
Fri Dec 07, 2018 1:45 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Are all pH calculations done to 2 decimal places or do we use sig figs in pH calculations? [ENDORSED]
Replies: 2
Views: 209

### Re: Are all pH calculations done to 2 decimal places or do we use sig figs in pH calculations?[ENDORSED]

pH calculations only follow sig figs after the decimal point! so two sig figs after the decimal point makes sense.
Mon Nov 19, 2018 6:34 pm
Forum: Hybridization
Topic: Sigma/Pi bonds
Replies: 6
Views: 374

### Re: Sigma/Pi bonds

A sigma bond (σ bond) is a bond formed by the overlap of orbitals in an end-to-end fashion, with the electron density concentrated between the nuclei of the bonding atoms. A pi bond (π bond) is a bond formed by the overlap of orbitals in a side-by-side fashion with the electron density concentrated...
Mon Nov 19, 2018 6:31 pm
Forum: Hybridization
Topic: electron density in regards to # of hybrid orbitals
Replies: 4
Views: 199

### Re: electron density in regards to # of hybrid orbitals

Think of it the other way around. The number of electron densities determine the hybridization. For example, 2 e- densities correspond with sp, 3 e- densities correspond with sp2, and so fourth. Keep in mind that once there are 5 e- densities, the hybridization becomes sp3d, or dsp3. We know this fr...
Mon Nov 19, 2018 6:26 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angle
Replies: 8
Views: 328

### Re: Bond Angle

Why is the axial bond angle of a seesaw molecule less than 180 degrees but the axial bond angle of a T shape molecule is 180 degrees? Does the T shape molecule not also experience electron repulsions from the lone pairs in the equitorial plane? The seesaw bond angle is less than 180 because there a...
Sun Nov 11, 2018 9:16 pm
Forum: General Science Questions
Topic: BruinCast [ENDORSED]
Replies: 4
Views: 418

### Re: BruinCast[ENDORSED]

Does anyone know any chem professors who do bruincast? Like for 14b/c/d?
Sun Nov 11, 2018 9:15 pm
Forum: Student Social/Study Group
Topic: Study Group Chat?
Replies: 4
Views: 331

### Study Group Chat?

I was wondering if there was a Chem 14A group chat on facebook or even a group me? If not is anyone willing to join?
Sun Nov 04, 2018 2:04 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge
Replies: 3
Views: 180

### Re: Formal Charge

The key is to minimize the charges to the charge of the molecule given. An quicker way to see the formal charge of an atom is to: 1) Find out how many valence electrons there is and 2) subtract the number of dots (lone pair electrons, count each one) and lines (shared bonds) around it.
Sun Nov 04, 2018 1:59 pm
Forum: Administrative Questions and Class Announcements
Topic: MIDTERM PRACTICE - Garlic Bread Review Session [ENDORSED]
Replies: 121
Views: 7070

### Re: MIDTERM PRACTICE - Garlic Bread Review Session[ENDORSED]

@Kevin Tang, This is because Chromium strives to fulfill the half-filled orbital energy, making it more stable. So instead of 3p4 4s2, it is 3p5 4s1. This is (I think) the only exception when it comes to electron configuration. (as well as all elements in the same group.)
Sun Nov 04, 2018 1:59 pm
Forum: Administrative Questions and Class Announcements
Topic: MIDTERM PRACTICE - Garlic Bread Review Session [ENDORSED]
Replies: 121
Views: 7070

### Re: MIDTERM PRACTICE - Garlic Bread Review Session[ENDORSED]

@Kevin Tang, This is because Chromium strives to fulfill the half-filled orbital energy, making it more stable. So instead of 3p4 4s2, it is 3p5 4s1. This is (I think) the only exception when it comes to electron configuration. (as well as all elements in the same group.)
Sun Nov 04, 2018 1:56 pm
Forum: Administrative Questions and Class Announcements
Topic: MIDTERM PRACTICE - Garlic Bread Review Session [ENDORSED]
Replies: 121
Views: 7070

### Re: MIDTERM PRACTICE - Garlic Bread Review Session[ENDORSED]

He really is too good. THE MVP!!!
Sun Oct 28, 2018 4:36 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8199
Views: 1430058

### Re: Post All Chemistry Jokes Here

I'd be the photon to your electron and take you to an excited state.
Sun Oct 28, 2018 4:30 pm
Forum: Ionic & Covalent Bonds
Topic: the Octet rule
Replies: 21
Views: 1166

### Re: the Octet rule

Yes they always look for the full octet.
Sun Oct 28, 2018 4:26 pm
Forum: *Shrodinger Equation
Topic: Using the Schrodinger Equation
Replies: 3
Views: 446

### Re: Using the Schrodinger Equation

You use the Schrodinger equation to find the allowed energy levels of quantum mechanical systems, like atoms. The wavefunction gives the probability of finding the particle at a certain position x. However, I do not think we are required to know exactly how it works for an exam/test
Sun Oct 21, 2018 4:30 pm
Forum: Quantum Numbers and The H-Atom
Topic: spin part of orbitals?
Replies: 5
Views: 205

### Re: spin part of orbitals?

Lavelle introduced spin by explaining the electron spin experiment in class. It just demonstrates the spin on the electron, but nothing to do with the orbital itself.
Sun Oct 21, 2018 4:27 pm
Topic: Test
Replies: 9
Views: 790

### Re: Test

I asked my TA and black body radiation is not focused on in this class, let alone for this test. I think Lavelle just mentioned it in class to prove a point.
Sun Oct 21, 2018 4:26 pm
Forum: Properties of Light
Topic: Test 2
Replies: 7
Views: 359

### Re: Test 2

Adding onto this, my TA said that test 2 is going to be a lot more conceptual based, so I think it's important to study the concepts that Lavelle goes through in class.
Sun Oct 14, 2018 10:20 pm
Forum: Properties of Light
Topic: C=Wavelength*Frequency
Replies: 11
Views: 735

### Re: C=Wavelength*Frequency

C is the constant for the speed of light. 3.00 x 10^8 m/s
Sun Oct 14, 2018 10:17 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8199
Views: 1430058

### Re: Post All Chemistry Jokes Here

What kind of fish is made out of two sodium ions?

2 Na.
Sun Oct 14, 2018 10:15 pm
Forum: General Science Questions
Topic: Rusty on High School Chem [ENDORSED]
Replies: 200
Views: 140864

### Re: Rusty on High School Chem[ENDORSED]

I'm in the same position. I'm sure that as long this course isn't taken lightly and you try your hardest, utilizing all of the resources given to us, you will do well!
Thu Oct 04, 2018 8:11 pm
Forum: Empirical & Molecular Formulas
Topic: F5 (6TH EDITION)
Replies: 5
Views: 273

### Re: F5 (6TH EDITION)

You have to find the overall mass of C7H15NO3, then divide that mass by the mass of each element. Remember each atom too, for example, it's not just 1 Carbon you divide, but 7 (the mass).
Thu Oct 04, 2018 8:09 pm
Forum: Significant Figures
Topic: Determining Sig Figs
Replies: 6
Views: 239

### Determining Sig Figs

I get confused on when to "obey" the sig figs given in a question, and when not to. I overheard someone saying if there's multiplication, then you use the sig figs given in the question? Can someone clarify this for me, thanks.
Thu Oct 04, 2018 8:06 pm
Forum: Balancing Chemical Reactions
Topic: Order of balancing an equation
Replies: 8
Views: 324

### Re: Order of balancing an equation

To add on to this, for me it depends. If there is a longer molecule that you know is not balanced on both sides, I try to solve this first. If both sides are pretty simple, I just balance what I see in order from left to right.