CHEMISTRY COMMUNITY

Josephine Chan 1B

In part c, can someone explain to me why HI is the acid and CaO is the base please?

Josephine Chan 1B

I'm pretty sure only the things written in pen will be graded. If anything, start with pencil and then write out your answer in pen when you're confident with it.

Josephine Chan 1B

It always helps to draw out the lewis structure and see if it can form a bond to the transition metal in two places at the same time

Josephine Chan 1B

How can you tell if a compound is a bronsted acid or base without looking at the chemical equation? I know an acid loses a proton and a base gains one, but how can you tell if it loses or gains one in the first place?

Josephine Chan 1B

Hi can someone explain how to find oxidation numbers like in 17.29 (6th edition) for example? thanks

Josephine Chan 1B

The greater the electronegativity difference there is between two atoms, the more ionic it is and the less covalent it is. So the less difference in electronegativity, the more covalent character it has.

Josephine Chan 1B

this was pretty helpful for me
http://www.chemistry.wustl.edu/~edudev/ ... _comp.html

Josephine Chan 1B

a head-on/linear overlap (sigma bond) will be stronger as opposed to a perpendicular/sideways overlap (pi bond)

Josephine Chan 1B

in which situations exactly do dipole cancel each other out?

Josephine Chan 1B

when do you know to include d in hybridized orbitals?

Josephine Chan 1B

Here's the link to the syllabus where it gives all of the outlines

https://lavelle.chem.ucla.edu/wp-conten ... SYLL_1.pdf

Josephine Chan 1B

Selina Bellin 3F wrote:does anyone know if the vsepr chart is in the textbook?

I believe it's on pg 103 in the seventh edition

Josephine Chan 1B

Dipole moments occur when there is a difference in electronegativity. It is a measurement of the separation of the two opposite electrical charges.

Josephine Chan 1B

Why is interaction potential energy always negative?

Josephine Chan 1B

Can someone please clarify what the concept of an induced dipole is? Is it different from a regular dipole? thank you

Josephine Chan 1B

Here's the link to the sig figs guideline from the class website

https://lavelle.chem.ucla.edu/wp-conten ... OUT_SF.pdf

Josephine Chan 1B

In class he said that hydrogen, helium, lithium, and beryllium are exceptions as well

Josephine Chan 1B

Transition metals are a little bit different. For transition metals like iron, the amount of valence electrons they have depends on the number of electrons they have after the noble gas core. So for iron: [Ar] 4s^2 3d^6, there are 8 electrons after the noble gas core so it has 8 valence electrons.

Josephine Chan 1B

That formula is specifically for kinetic energy so don't think it can be used for other types of energy.

Josephine Chan 1B

lukezhang1K wrote:Which equations do we have to memorise vs which ones are on the equation sheet?

I'm pretty sure all the equations you'll need will be on the sheet so you don't have to memorize any of them you just have to know how to use them.

Josephine Chan 1B

Yeah, if youre talking about test 2 then it's very possible that there will be questions about orbitals.

Josephine Chan 1B

The principle quantum number determines the energy level and is also called the shell and is labeled as n. The magnetic quantum number labels different orbitals of a subshell and is labeled as mℓ.

Josephine Chan 1B

it says on the syllabus that the class does not use a curve. If you want, here's the link to the syllabus where you can read more about the grading/point system

https://lavelle.chem.ucla.edu/wp-conten ... SYLL_1.pdf

Josephine Chan 1B

I think he said we wont be doing calculations with it. He just wanted us to know about it for reference

Josephine Chan 1B

Im also confused about how to create a new post/topic. I feel like im missing something

Josephine Chan 1B

We only have the thursday and friday off (nov22-23)

Josephine Chan 1B

Yes, according to the test and exam schedule, we have the midterm on Nov 5 and then the next test is on the week after Thanksgiving break.

Josephine Chan 1B

Im not sure about 14b but for 14a, dr lavelle sent an email out about the class website with the password. So try checking the emails you got from the class email.

Josephine Chan 1B

I think in one of the lectures he said that if the number is less than 0.05 from the closest whole number, then its close enough to round it. If not then you probably just have to keep multiplying until you get close enough to the next whole number

Josephine Chan 1B

since the ratio of solid calcium carbide to water is 1:2(refer to balanced equation), 1.56 mol of calcium carbide requires 2 x 1.56 = 3.12 mol of water which is less than the 5.55 mol of water that we have. That means we have excess water and not enough calcium carbide. So calcium carbide is the lim...

Josephine Chan 1B

Im not sure when they are due but the assessment scores don't affect our grades at all. So it just matters if you do them or not.

CHEMISTRY COMMUNITY

Search found 31 matches

6th edition J.11

Re: Can We Take The Final In Pencil?

Re: Polydentate

Fundamentals J.1 Bronsted Acids and Bases

Oxidation number

Re: Covalent Character

Re: Naming Coordination Compounds

Re: Why are sigma bonds stronger than pi bonds?

canceling dipoles

d orbital

Re: Test 3

Re: Test 3

Re: How to Identify Dipole Moments

Interaction Potential Energy

induced-dipole

Re: Sig Figs on Midterm

Re: Boron and Aluminum

Re: Valence Electrons in the d-orbitals

Re: Kinetic energy

Re: Test 2

Re: Exam

Re: Vocabulary confusion

Re: curve?

Re: Schrodinger Equation

Re: How to find my posts

Re: Thanksgiving Week

Re: Test and Exam Dates

Re: Class Website Password

Re: When to double moles

Re: Limiting Reactants

Re: Audio-Visual Focus-Topics, Assessments & Surveys