Search found 20 matches

by Rebecca Cheung 1E
Thu Dec 07, 2017 4:50 pm
Forum: Amphoteric Compounds
Topic: Acidic, basic, or amphoteric? [ENDORSED]
Replies: 4
Views: 498

Re: Acidic, basic, or amphoteric? [ENDORSED]

"Where exactly is the line that separates metals from nonmetals?" Not sure what answer you're exactly looking for but in speaking in terms of properties, metals are conductive, malleable, and solid (at room temp) and non-metals are not conductive, brittle, and gaseous/liquid/solid (at room...
by Rebecca Cheung 1E
Thu Dec 07, 2017 4:43 pm
Forum: Lewis Acids & Bases
Topic: Identifying Lewis Acid
Replies: 3
Views: 173

Identifying Lewis Acid

Why is it important to list the oxidation state when identifying the Lewis Acid? For example, for the Lewis Structure [PtCl4(NH3)2], the Lewis Acid is Pt(IV). Why would it be wrong to just put Pt? thanks
by Rebecca Cheung 1E
Thu Dec 07, 2017 4:34 pm
Forum: Bronsted Acids & Bases
Topic: Single arrow vs. double arrows
Replies: 2
Views: 177

Re: Single arrow vs. double arrows

Maybe it is because H2SO4 is a polyprotic acid so it has the potential to donate more protons instead of one?
by Rebecca Cheung 1E
Thu Dec 07, 2017 4:21 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Formic Acid and Acetic Acid
Replies: 2
Views: 278

Re: Formic Acid and Acetic Acid

I'm not really sure but I found this link on Google that may be able to help: https://chemistry.stackexchange.com/que ... cetic-acid
by Rebecca Cheung 1E
Wed Nov 29, 2017 8:06 pm
Forum: Conjugate Acids & Bases
Topic: Chemical Formula
Replies: 5
Views: 241

Re: Chemical Formula

If it's a metal it's a base. If it's a nonmetal it's an acid. For example, KOH and NaOH are bases because they contain alkaline earth metals. HBr and HCl are acids because they contain nonmetals.
by Rebecca Cheung 1E
Wed Nov 29, 2017 8:02 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: ICE box
Replies: 3
Views: 306

Re: ICE box

-x applies to the reactants and +x applies to the products.
by Rebecca Cheung 1E
Sun Nov 19, 2017 4:57 pm
Forum: Hybridization
Topic: Shape of Hybrid Orbitals?
Replies: 2
Views: 116

Shape of Hybrid Orbitals?

Do hybrid orbitals have a shape? We know the shape of pi and sigma bonds, and I was curious what kind of shape do hybrid orbitals have.
by Rebecca Cheung 1E
Sun Nov 19, 2017 4:07 pm
Forum: Lewis Structures
Topic: Lewis Structure of CO
Replies: 2
Views: 117

Re: Lewis Structure of CO

The second structure is right because carbon needs an octet. In the first structure, carbon needs two more electrons to fufill the octet rule.
by Rebecca Cheung 1E
Sun Nov 12, 2017 3:33 pm
Forum: Lewis Structures
Topic: atomic structure of HOCO
Replies: 8
Views: 276

Re: atomic structure of HOCO

The H in the molecular formula is next to the O, so when you draw out the lewis structure, you would draw the H bonded with the O and not with C.
by Rebecca Cheung 1E
Sun Nov 12, 2017 3:27 pm
Forum: Dipole Moments
Topic: Dipole Moments
Replies: 2
Views: 126

Re: Dipole Moments

When dipole moments point directly to each other or away from each other with the same strength, they cancel. If they point directly to each other or away, but with different dipole moment strengths the dipole moments wouldn't cancel.
by Rebecca Cheung 1E
Sun Nov 12, 2017 3:07 pm
Forum: Lewis Structures
Topic: Midterm Question CH3SH
Replies: 5
Views: 241

Midterm Question CH3SH

So I bonded carbon with 3 hydrogens and bonded carbon with sulfur (sulfur has 2 lone pairs) and bonded sulfur with hydrogen. It has a total of 14 e-. Just wanted to compare and check if I got this right. Thanks!
by Rebecca Cheung 1E
Mon Nov 06, 2017 5:28 pm
Forum: Lewis Structures
Topic: Lone Pairs and H2O
Replies: 2
Views: 135

Lone Pairs and H2O

Can someone help clarify why the shape of H2O is not linear but bent? Thanks in advance.
by Rebecca Cheung 1E
Sun Oct 29, 2017 4:56 pm
Forum: Quantum Numbers and The H-Atom
Topic: Valence electrons [ENDORSED]
Replies: 7
Views: 333

Re: Valence electrons [ENDORSED]

Yes, those are the outermost electrons (valence e-).
by Rebecca Cheung 1E
Sun Oct 29, 2017 4:53 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Determining Formal Charge [ENDORSED]
Replies: 3
Views: 204

Re: Determining Formal Charge [ENDORSED]

Formal charge of 0 corresponds to lower energy and is more stable.
by Rebecca Cheung 1E
Sat Oct 21, 2017 10:47 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: s-electrons and p-electrons [ENDORSED]
Replies: 2
Views: 150

Re: s-electrons and p-electrons [ENDORSED]

Because of the different shapes of s and p orbitals, in a multi-electron system the energy of s-orbitals is lower than the energy of p-orbitals because of the small differences in attraction they feel from the nucleus. S-orbitals is spherical and symmetrical with no nodal planes, while p-orbitals ar...
by Rebecca Cheung 1E
Mon Oct 16, 2017 7:46 pm
Forum: Photoelectric Effect
Topic: Post Module #19
Replies: 3
Views: 173

Post Module #19

Which one of following is not describing the photoelectric effect?

A. E (photon) – E (remove e-) = E (excess)
B. E (photon) – E (remove e-) = EK (e-)
C. hv - work function = 1/2mv2
D. λv = c
E. None of the above

What is the answer to this and can someone explain why? Thanks!
by Rebecca Cheung 1E
Fri Oct 13, 2017 9:56 am
Forum: Photoelectric Effect
Topic: Kinetic energy equal to zero?
Replies: 4
Views: 318

Kinetic energy equal to zero?

How do you know when to set the kinetic energy equal to zero? What's the key information they give you? thanks!
by Rebecca Cheung 1E
Fri Oct 13, 2017 9:50 am
Forum: Properties of Electrons
Topic: Threshold level and Work Function [ENDORSED]
Replies: 6
Views: 388

Threshold level and Work Function [ENDORSED]

Threshold level and Work Function are basically the same thing right?
by Rebecca Cheung 1E
Thu Oct 05, 2017 9:46 pm
Forum: Administrative Questions and Class Announcements
Topic: Where to find Bruincast?
Replies: 3
Views: 297

Where to find Bruincast?

Hi, where can I find the link to Bruincast? Will we have it this year? Not really sure how this works. If someone can explain, thanks!
by Rebecca Cheung 1E
Tue Oct 03, 2017 5:02 pm
Forum: Empirical & Molecular Formulas
Topic: Problem E5
Replies: 6
Views: 616

Problem E5

(A) The approximate population of Earth is 7.0 billion people. How many moles of people inhabit Earth? (B) If all people were pea pickers, how long would it take for the entire population of Earth to pick 1 mol of peas at the rate of one pea per second, working 24 hours per day, 365 days per year? O...

Go to advanced search