Search found 29 matches

by AlyssaRivera
Thu Jun 14, 2018 8:04 am
Forum: General Science Questions
Topic: Bond angles
Replies: 4
Views: 374

Re: Bond angles

Something I used to help memorize is once you get the basic shapes down (ones without lone pairs), once you get to the shapes with lone pairs, the bond angles are similar but for exmaple A trigonal planar is AX3 and an angular shaped molecule is AX2E. Both have three regions of electron density. Tr...
by AlyssaRivera
Thu Jun 14, 2018 8:03 am
Forum: Hybridization
Topic: How to figure out hybridization
Replies: 5
Views: 668

Re: How to figure out hybridization

when we look at so2 we know that it has three things attached (when you include the lone pair) to the central atom, S. this means that we are going to fill up three regions, starting with the s-orbital and moving onto the p orbital. We'll get sp2 for the hybridization. When we look at the VSEPR form...
by AlyssaRivera
Mon Jun 11, 2018 9:28 pm
Forum: Resonance Structures
Topic: How to tell when an molecule is resonant?
Replies: 7
Views: 333

Re: How to tell when an molecule is resonant?

Yitzchak Jacobson 1F wrote:you can tell when a molecule is resonant by knowing if there are multiple ways to draw the lewis structure.
Hope this helps you :)

does this simply mean changing around where elements are places on the central atom or which types of bonds are there?
by AlyssaRivera
Mon Jun 11, 2018 9:26 pm
Forum: General Science Questions
Topic: Sig Figs
Replies: 9
Views: 879

Re: Sig Figs

throughout the problem, how many sig figs should we use when plugging things into our calculator? I've gotten different answers on some problems by rounding things that I plug in
by AlyssaRivera
Mon Jun 11, 2018 9:23 pm
Forum: General Science Questions
Topic: ionization energy versus electron affinity
Replies: 1
Views: 146

ionization energy versus electron affinity

I know that these have the same periodic trends, but what exactly is the difference between the two? Also, what type of questions besides conceptual ones would be asked regarding them?
by AlyssaRivera
Mon Jun 11, 2018 9:20 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Charge of ligands
Replies: 5
Views: 216

Re: Charge of ligands

Sarai Ventura 1L wrote:Yes I think it would be helpful to know the charges to save time and I think you should know the common ones.
will we lose credit by just having them memorized and not writing out how we came to the answer?
by AlyssaRivera
Mon Jun 11, 2018 9:18 pm
Forum: Administrative Questions and Class Announcements
Topic: Review Sessions Finals Week - Hedrick Hall? [ENDORSED]
Replies: 6
Views: 396

Re: Review Sessions Finals Week - Hedrick Hall? [ENDORSED]

I couldn't find them either. I'm not sure if I was in the correct location. Luckily, there are many sessions tomorrow as well as Wednesday.
by AlyssaRivera
Mon Jun 11, 2018 9:14 pm
Forum: General Science Questions
Topic: Bond angles
Replies: 4
Views: 374

Bond angles

Should we memorize bond angles for different structures? If so, which are the most important to memorize?
by AlyssaRivera
Sun Jun 03, 2018 11:00 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Naming shape
Replies: 7
Views: 253

Re: Naming shape

You have to take the lone pairs into consideration as well. As mentioned previously, you should memorize the AXE formula. The E in this formula represents the lone pairs. It can change the shape of the molecule a lot.
by AlyssaRivera
Sat Jun 02, 2018 11:03 pm
Forum: Sigma & Pi Bonds
Topic: What is a localized and delocalized Bond?
Replies: 5
Views: 9690

Re: What is a localized and delocalized Bond?

To simplify it, localized bonds are bonds formed by two overlapping molecular orbitals
by AlyssaRivera
Sat Jun 02, 2018 11:00 pm
Forum: Sigma & Pi Bonds
Topic: Relationship between Sigma and Pi bondss
Replies: 2
Views: 230

Re: Relationship between Sigma and Pi bondss

I believe there can only be one sigma bond in both double and triple bonds.
by AlyssaRivera
Sat May 26, 2018 9:57 pm
Forum: Octet Exceptions
Topic: Octet exceptions and Formal charges.
Replies: 6
Views: 364

Re: Octet exceptions and Formal charges.

Elements that do not follow the octet rule is one of the biggest reason why we use the formal charge equations. Because these elements do not follow the typical trends that others do, this formula provides an accurate charge to use when trying to make a stable, or the most stable form of a lewis str...
by AlyssaRivera
Sat May 26, 2018 9:52 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal charge purpose
Replies: 40
Views: 1450

Re: Formal charge purpose

As Professor Lavelle has explained, you want to have the lewis structure in the most stable form. It's important to know what each individual elements charge is because it determines where the element should be placed in the structure.
by AlyssaRivera
Sat May 26, 2018 9:34 pm
Forum: Formal Charge and Oxidation Numbers
Topic: formal charge
Replies: 11
Views: 448

Re: formal charge

Finding the formal charge is super simple, even though the formula may look complicated. The formula is FC=V-(L+B/2) You take the lewis structure for the problem you are doing and look at the specific element that you're solving for, plug in the number of valence electrons that it should have based ...
by AlyssaRivera
Sun May 13, 2018 5:53 pm
Forum: Balancing Chemical Reactions
Topic: Whole numbers
Replies: 7
Views: 326

Re: Whole numbers

Subscripts must always be whole numbers. The ratio of moles in the equation but it will never be lower than the empirical formula and the amount of moles seen there.
by AlyssaRivera
Sun May 13, 2018 5:51 pm
Forum: Balancing Chemical Reactions
Topic: Suggestions for Balancing Reactions
Replies: 8
Views: 369

Re: Suggestions for Balancing Reactions

A trick I tend to do somewhere on the side of my paper for extra help is creating a t-chart & tallying the amount of moles of each element I have for each side. It's a nice, visual way to make sure you're balanced!
by AlyssaRivera
Sun May 13, 2018 5:48 pm
Forum: Limiting Reactant Calculations
Topic: Test 1
Replies: 4
Views: 239

Re: Test 1

No but you can go to your office hours to review your own personal tests! Highly recommend
by AlyssaRivera
Sun May 13, 2018 5:46 pm
Forum: Limiting Reactant Calculations
Topic: Mass of Reactant/Product
Replies: 4
Views: 314

Re: Mass of Reactant/Product

No, reactants Never weigh more than the mass of the products because of conservation of mass.
by AlyssaRivera
Sun Apr 29, 2018 5:12 pm
Forum: Student Social/Study Group
Topic: Chemistry News
Replies: 60
Views: 37102

Re: Chemistry News

Primeval Salt Shakes Up Ideas on How the Atmosphere Got Its Oxygen:
https://www.scientificamerican.com/arti ... ts-oxygen/
by AlyssaRivera
Sun Apr 29, 2018 5:04 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: What does electron spin actually mean? [ENDORSED]
Replies: 9
Views: 378

Re: What does electron spin actually mean? [ENDORSED]

Electron spin is the way that the electron spins within the magnetic field.
by AlyssaRivera
Sun Apr 29, 2018 5:03 pm
Forum: Student Social/Study Group
Topic: Rieber Vista(Or any of the Riebers') Chem 14A Study Group Fall 2017
Replies: 6
Views: 533

Re: Rieber Vista(Or any of the Riebers') Chem 14A Study Group Fall 2017

Is anyone interested in starting this for the 2018 Spring Quarter?
by AlyssaRivera
Sun Apr 22, 2018 9:37 am
Forum: Significant Figures
Topic: Sig Fig Accuracy [ENDORSED]
Replies: 6
Views: 357

Re: Sig Fig Accuracy [ENDORSED]

Are sig figs going to need to be accurate on test #2?
by AlyssaRivera
Sun Apr 22, 2018 9:36 am
Forum: Student Social/Study Group
Topic: Study Group
Replies: 10
Views: 643

Re: Study Group

I'm definitely interested in this! If anyone else would like to have more study groups as well let me know! Possibly even on the weekends.
by AlyssaRivera
Sun Apr 22, 2018 9:32 am
Forum: General Science Questions
Topic: Rusty on High School Chem [ENDORSED]
Replies: 166
Views: 100948

Re: Rusty on High School Chem [ENDORSED]

Khan academy as well as youtube videos called "chemistry crash course" by one of the Green brothers. He goes over fundamentals as well as more complex ideas in chemistry as well as other subjects.
by AlyssaRivera
Sun Apr 15, 2018 10:51 am
Forum: Ideal Gases
Topic: Reading the textbook [ENDORSED]
Replies: 127
Views: 75149

Re: Reading the textbook [ENDORSED]

How useful is studying from the textbook in regards to test taking? Are tutoring/lecture notes better to study from?
by AlyssaRivera
Sun Apr 15, 2018 10:49 am
Forum: Administrative Questions and Class Announcements
Topic: Tutoring? [ENDORSED]
Replies: 61
Views: 53651

Re: Tutoring? [ENDORSED]

Are there any other tutoring programs similar to AAP?
by AlyssaRivera
Sun Apr 15, 2018 10:44 am
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7582
Views: 1017218

Re: Post All Chemistry Jokes Here

Two chemists go into a bar. The first one says "I think I'll have an H2O." The second one says "I think I'll have an H2O too" — and he died.
by AlyssaRivera
Fri Apr 13, 2018 12:01 pm
Forum: Limiting Reactant Calculations
Topic: Two limiting reactants?
Replies: 10
Views: 780

Re: Two limiting reactants?

No, because if there were multiple limiting reactants, there would be no excess products.
by AlyssaRivera
Thu Apr 12, 2018 11:57 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Molar Mass
Replies: 9
Views: 428

Re: Molar Mass

Atomic mass is the mass of an individual atom but molar mass is the mass of one mole of an atom.

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