Search found 31 matches

by Josephine Chan 1B
Tue Dec 04, 2018 8:46 pm
Forum: Bronsted Acids & Bases
Topic: 6th edition J.11
Replies: 1
Views: 51

6th edition J.11

In part c, can someone explain to me why HI is the acid and CaO is the base please?
by Josephine Chan 1B
Tue Dec 04, 2018 8:11 pm
Forum: General Science Questions
Topic: Can We Take The Final In Pencil?
Replies: 8
Views: 310

Re: Can We Take The Final In Pencil?

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.
by Josephine Chan 1B
Tue Dec 04, 2018 8:08 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Polydentate
Replies: 1
Views: 41

Re: Polydentate

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
by Josephine Chan 1B
Sun Dec 02, 2018 8:58 pm
Forum: Bronsted Acids & Bases
Topic: Fundamentals J.1 Bronsted Acids and Bases
Replies: 2
Views: 76

Fundamentals J.1 Bronsted Acids and Bases

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?
by Josephine Chan 1B
Fri Nov 30, 2018 9:56 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Oxidation number
Replies: 1
Views: 63

Oxidation number

Hi can someone explain how to find oxidation numbers like in 17.29 (6th edition) for example? thanks
by Josephine Chan 1B
Fri Nov 30, 2018 9:47 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Covalent Character
Replies: 2
Views: 113

Re: Covalent Character

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.
by Josephine Chan 1B
Fri Nov 30, 2018 9:41 pm
Forum: Naming
Topic: Naming Coordination Compounds
Replies: 1
Views: 52

Re: Naming Coordination Compounds

by Josephine Chan 1B
Sun Nov 25, 2018 8:53 am
Forum: Sigma & Pi Bonds
Topic: Why are sigma bonds stronger than pi bonds?
Replies: 10
Views: 274

Re: Why are sigma bonds stronger than pi bonds?

a head-on/linear overlap (sigma bond) will be stronger as opposed to a perpendicular/sideways overlap (pi bond)
by Josephine Chan 1B
Sun Nov 25, 2018 8:45 am
Forum: Dipole Moments
Topic: canceling dipoles
Replies: 2
Views: 64

canceling dipoles

in which situations exactly do dipole cancel each other out?
by Josephine Chan 1B
Sun Nov 25, 2018 8:41 am
Forum: Hybridization
Topic: d orbital
Replies: 2
Views: 50

d orbital

when do you know to include d in hybridized orbitals?
by Josephine Chan 1B
Sun Nov 18, 2018 12:18 am
Forum: Hybridization
Topic: Test 3
Replies: 5
Views: 128

Re: Test 3

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

https://lavelle.chem.ucla.edu/wp-conten ... SYLL_1.pdf
by Josephine Chan 1B
Sun Nov 18, 2018 12:10 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Test 3
Replies: 19
Views: 292

Re: Test 3

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
by Josephine Chan 1B
Sat Nov 17, 2018 11:52 pm
Forum: Dipole Moments
Topic: How to Identify Dipole Moments
Replies: 3
Views: 93

Re: How to Identify Dipole Moments

Dipole moments occur when there is a difference in electronegativity. It is a measurement of the separation of the two opposite electrical charges.
by Josephine Chan 1B
Sun Nov 11, 2018 12:41 am
Forum: Bond Lengths & Energies
Topic: Interaction Potential Energy
Replies: 2
Views: 108

Interaction Potential Energy

Why is interaction potential energy always negative?
by Josephine Chan 1B
Sun Nov 11, 2018 12:31 am
Forum: Dipole Moments
Topic: induced-dipole
Replies: 3
Views: 236

induced-dipole

Can someone please clarify what the concept of an induced dipole is? Is it different from a regular dipole? thank you
by Josephine Chan 1B
Sun Nov 11, 2018 12:28 am
Forum: Student Social/Study Group
Topic: Sig Figs on Midterm
Replies: 13
Views: 472

Re: Sig Figs on Midterm

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

https://lavelle.chem.ucla.edu/wp-conten ... OUT_SF.pdf
by Josephine Chan 1B
Fri Nov 02, 2018 5:09 pm
Forum: Octet Exceptions
Topic: Boron and Aluminum
Replies: 2
Views: 67

Re: Boron and Aluminum

In class he said that hydrogen, helium, lithium, and beryllium are exceptions as well
by Josephine Chan 1B
Fri Nov 02, 2018 5:03 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Valence Electrons in the d-orbitals
Replies: 2
Views: 53

Re: Valence Electrons in the d-orbitals

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.
by Josephine Chan 1B
Fri Nov 02, 2018 4:55 pm
Forum: Photoelectric Effect
Topic: Kinetic energy
Replies: 11
Views: 2146

Re: Kinetic energy

That formula is specifically for kinetic energy so don't think it can be used for other types of energy.
by Josephine Chan 1B
Thu Oct 25, 2018 11:59 pm
Forum: Properties of Light
Topic: Test 2
Replies: 7
Views: 247

Re: Test 2

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.
by Josephine Chan 1B
Thu Oct 25, 2018 11:56 pm
Forum: Administrative Questions and Class Announcements
Topic: Exam
Replies: 7
Views: 235

Re: Exam

Yeah, if youre talking about test 2 then it's very possible that there will be questions about orbitals.
by Josephine Chan 1B
Thu Oct 25, 2018 11:53 pm
Forum: Quantum Numbers and The H-Atom
Topic: Vocabulary confusion
Replies: 2
Views: 139

Re: Vocabulary confusion

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.
by Josephine Chan 1B
Fri Oct 19, 2018 1:40 pm
Forum: Student Social/Study Group
Topic: curve?
Replies: 20
Views: 826

Re: curve?

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
by Josephine Chan 1B
Fri Oct 19, 2018 1:35 pm
Forum: *Shrodinger Equation
Topic: Schrodinger Equation
Replies: 2
Views: 70

Re: Schrodinger Equation

I think he said we wont be doing calculations with it. He just wanted us to know about it for reference
by Josephine Chan 1B
Wed Oct 17, 2018 1:20 pm
Forum: Administrative Questions and Class Announcements
Topic: How to find my posts
Replies: 28
Views: 24002

Re: How to find my posts

Im also confused about how to create a new post/topic. I feel like im missing something
by Josephine Chan 1B
Tue Oct 09, 2018 11:54 pm
Forum: General Science Questions
Topic: Thanksgiving Week
Replies: 8
Views: 281

Re: Thanksgiving Week

We only have the thursday and friday off (nov22-23)
by Josephine Chan 1B
Tue Oct 09, 2018 8:48 pm
Forum: SI Units, Unit Conversions
Topic: Test and Exam Dates
Replies: 10
Views: 391

Re: Test and Exam Dates

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.
by Josephine Chan 1B
Tue Oct 09, 2018 8:41 pm
Forum: Administrative Questions and Class Announcements
Topic: Class Website Password
Replies: 2
Views: 139

Re: Class Website Password

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.
by Josephine Chan 1B
Wed Oct 03, 2018 1:33 pm
Forum: Empirical & Molecular Formulas
Topic: When to double moles
Replies: 13
Views: 194

Re: When to double moles

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
by Josephine Chan 1B
Wed Oct 03, 2018 1:29 pm
Forum: Limiting Reactant Calculations
Topic: Limiting Reactants
Replies: 2
Views: 53

Re: Limiting Reactants

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...
by Josephine Chan 1B
Mon Oct 01, 2018 9:16 pm
Forum: SI Units, Unit Conversions
Topic: Audio-Visual Focus-Topics, Assessments & Surveys
Replies: 10
Views: 261

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

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.

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