CHEMISTRY COMMUNITY

AlyssaRivera

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...

AlyssaRivera

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...

AlyssaRivera

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?

AlyssaRivera

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

AlyssaRivera

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?

AlyssaRivera

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?

AlyssaRivera

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.

AlyssaRivera

Should we memorize bond angles for different structures? If so, which are the most important to memorize?

AlyssaRivera

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.

AlyssaRivera

To simplify it, localized bonds are bonds formed by two overlapping molecular orbitals

AlyssaRivera

I believe there can only be one sigma bond in both double and triple bonds.

AlyssaRivera

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...

AlyssaRivera

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.

AlyssaRivera

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 ...

AlyssaRivera

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.

AlyssaRivera

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!

AlyssaRivera

No but you can go to your office hours to review your own personal tests! Highly recommend

AlyssaRivera

No, reactants Never weigh more than the mass of the products because of conservation of mass.

AlyssaRivera

Primeval Salt Shakes Up Ideas on How the Atmosphere Got Its Oxygen:
https://www.scientificamerican.com/arti ... ts-oxygen/

AlyssaRivera

Electron spin is the way that the electron spins within the magnetic field.

AlyssaRivera

Is anyone interested in starting this for the 2018 Spring Quarter?

AlyssaRivera

Are sig figs going to need to be accurate on test #2?

AlyssaRivera

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.

AlyssaRivera

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.

AlyssaRivera

How useful is studying from the textbook in regards to test taking? Are tutoring/lecture notes better to study from?

AlyssaRivera

Are there any other tutoring programs similar to AAP?

AlyssaRivera

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.

AlyssaRivera

No, because if there were multiple limiting reactants, there would be no excess products.

AlyssaRivera

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

CHEMISTRY COMMUNITY

Search found 29 matches

Re: Bond angles

Re: How to figure out hybridization

Re: How to tell when an molecule is resonant?

Re: Sig Figs

ionization energy versus electron affinity

Re: Charge of ligands

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

Bond angles

Re: Naming shape

Re: What is a localized and delocalized Bond?

Re: Relationship between Sigma and Pi bondss

Re: Octet exceptions and Formal charges.

Re: Formal charge purpose

Re: formal charge

Re: Whole numbers

Re: Suggestions for Balancing Reactions

Re: Test 1

Re: Mass of Reactant/Product

Re: Chemistry News

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

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

Re: Sig Fig Accuracy [ENDORSED]

Re: Study Group

Re: Rusty on High School Chem [ENDORSED]

Re: Reading the textbook

Re: Tutoring? [ENDORSED]

Re: Post All Chemistry Jokes Here

Re: Two limiting reactants?

Re: Molar Mass