Search found 29 matches

by hannahtweedy
Thu Jun 14, 2018 1:49 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Charge on ligands? [ENDORSED]
Replies: 2
Views: 182

Re: Charge on ligands? [ENDORSED]

Don't you find the oxidation of the metal then match it equally and with an opposite charge for the ligand?
by hannahtweedy
Wed Jun 13, 2018 7:31 pm
Forum: Administrative Questions and Class Announcements
Topic: Final Exam [ENDORSED]
Replies: 5
Views: 301

Re: Final Exam [ENDORSED]

The general review sessions have had a bit of everything... But incorporate multiple chapters in one question
by hannahtweedy
Sat Jun 02, 2018 6:30 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: formal charge and VSEPR
Replies: 8
Views: 263

Re: formal charge and VSEPR

It's better to do it this way... but does anybody know if it's a necessity to be correct?
by hannahtweedy
Sat Jun 02, 2018 6:24 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Define Ligands?
Replies: 10
Views: 317

Re: Define Ligands?

What kind of thing do you think we could be asked regarding ligands
by hannahtweedy
Mon May 28, 2018 1:53 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge Meaning
Replies: 5
Views: 297

Re: Formal Charge Meaning

Does that mean that formal charge and the dipole movement are related/similar concepts?
by hannahtweedy
Thu May 24, 2018 8:18 pm
Forum: Lewis Acids & Bases
Topic: Lewis acid vs. base
Replies: 5
Views: 196

Re: Lewis acid vs. base

Also if you do a Lewis structure, and there are unbonded valence electrons on the central atom, it's a Lewis base
by hannahtweedy
Thu May 24, 2018 5:38 pm
Forum: Ionic & Covalent Bonds
Topic: Formal charge?
Replies: 12
Views: 467

Re: Formal charge?

Would the equation:

valence electrons - non-bonding valence electrons - (bonding electrons/2)

also work?
by hannahtweedy
Sat May 12, 2018 5:59 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Oxidation Number & Bonds
Replies: 6
Views: 222

Re: Oxidation Number & Bonds

I would believe so? Sort of like whichever value is easiest to achieve with the elements at hand to achieve the desired results
by hannahtweedy
Thu May 10, 2018 9:06 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: E=R(1/n-1/n)?
Replies: 7
Views: 337

Re: E=R(1/n-1/n)?

E=R(1/n2^2-1/n1^2) is the equation to specifically find the change in energy. The E= -hR/n^2 is for one specific energy level
by hannahtweedy
Thu May 10, 2018 8:58 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: De Broglie Equation in Heisenberg Uncertainty Equation
Replies: 2
Views: 219

Re: De Broglie Equation in Heisenberg Uncertainty Equation

I would assume it's possible because both involve the wave-like nature of light. I would think you could possibly include Schrodinger's in there as well with them.
by hannahtweedy
Sun May 06, 2018 9:58 pm
Forum: Molarity, Solutions, Dilutions
Topic: Q. G5
Replies: 1
Views: 125

Re: Q. G5

a) First, you convert the mmol to mol - keeping in mind since there's 2 Na in Na2CO3 the molarity will be doubled. Then you can divide the values in the formula: 0.002015/0.16 --> 0.013 L
by hannahtweedy
Sun May 06, 2018 9:52 pm
Forum: Trends in The Periodic Table
Topic: Trends to Know
Replies: 12
Views: 484

Re: Trends to Know

All the ones listed so far are the only ones we went over in Step Up
by hannahtweedy
Sun May 06, 2018 9:45 pm
Forum: Student Social/Study Group
Topic: Midterm Study Group
Replies: 1
Views: 176

Midterm Study Group

Hi everybody!

There's a come-and-go study group this Tuesday from 3p until 7p in Sproul Hall's 6th Floor lounge. Anybody's welcome to come and leave whenever they would like to leave.
by hannahtweedy
Sun Apr 29, 2018 8:57 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: 2.25
Replies: 3
Views: 116

Re: 2.25

I just did it using the little equations!

Spherical nodes : n - l - 1
Number of angular nodes: l
Total nodes: n-1
by hannahtweedy
Sat Apr 28, 2018 8:58 pm
Forum: Quantum Numbers and The H-Atom
Topic: What do l and m represent? [ENDORSED]
Replies: 6
Views: 221

Re: What do l and m represent? [ENDORSED]

https://youtu.be/Aoi4j8es4gQ I found this video pretty helpful clarifying it all
by hannahtweedy
Sat Apr 28, 2018 8:55 pm
Forum: *Shrodinger Equation
Topic: Shrodinger Equation
Replies: 7
Views: 319

Re: Shrodinger Equation

According to the text book, it’s used to calculate the wave function for any particle and the corresponding energy E
by hannahtweedy
Sun Apr 22, 2018 9:30 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Balmer Series vs Lyman Series
Replies: 4
Views: 486

Re: Balmer Series vs Lyman Series

The Paschem series and Brackett series were also mentioned in a hw question. Can anybody explain these better?
by hannahtweedy
Sun Apr 22, 2018 9:25 pm
Forum: Student Social/Study Group
Topic: Study Group
Replies: 10
Views: 644

Re: Study Group

Follow the GroupMe link!
by hannahtweedy
Sun Apr 22, 2018 9:24 pm
Forum: Photoelectric Effect
Topic: Wave vs. Particle
Replies: 8
Views: 204

Re: Wave vs. Particle

Particles have mass while photons do not... both still have momentum though!
by hannahtweedy
Sun Apr 22, 2018 4:54 pm
Forum: Properties of Light
Topic: Question About Photons [ENDORSED]
Replies: 3
Views: 142

Re: Question About Photons [ENDORSED]

When this occurs would momentum still have the same function and measure as when mass exists?
by hannahtweedy
Sat Apr 14, 2018 10:04 pm
Forum: Student Social/Study Group
Topic: Study Group
Replies: 10
Views: 644

Re: Study Group

You're invited to my new group '14A - Lavelle' on GroupMe. Click here to join: https://groupme.com/join_group/39693612/gWBYOk

For scheduling only- leave content questions on chem community please
by hannahtweedy
Wed Apr 11, 2018 9:11 pm
Forum: Empirical & Molecular Formulas
Topic: Empirical Formula
Replies: 3
Views: 206

Re: Empirical Formula

More specifically, how would I find the mass percentages given a full balanced equation
by hannahtweedy
Wed Apr 11, 2018 5:31 pm
Forum: Empirical & Molecular Formulas
Topic: Empirical Formula
Replies: 3
Views: 206

Empirical Formula

Polyethylene is a hydrocarbon polymer used to produce food-storage bags and many other flexible plastic items. A combustion analysis of a 0.00126-g sample of polyethylene yields 0.00394-g of CO2 and 0.00161-g of H20. What is the empirical formula of polyethylene? I've balanced the equation but now I...
by hannahtweedy
Mon Apr 09, 2018 4:52 pm
Forum: Student Social/Study Group
Topic: Study Group
Replies: 10
Views: 644

Re: Study Group

Nancy, I emailed you!
by hannahtweedy
Thu Apr 05, 2018 3:13 pm
Forum: Balancing Chemical Reactions
Topic: H.5: Balancing Equations
Replies: 6
Views: 398

Re: H.5: Balancing Equations

So the best thing that I found, was to make a chart of the elements as I go Fe2P(s)+S(s)-->P4S10(s)+FeS(s) 2 - Fe - 1 1 - P - 4 1 - S - 11 The left has the number of elements in the reactant side and the right is the product side. As I balance one, I change it all the ones affected. For example, sta...
by hannahtweedy
Thu Apr 05, 2018 10:32 am
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: E.27
Replies: 2
Views: 122

Re: E.27

1: convert 1kg to 1000 g 2: you'll need to convert first to moles (value given of H20 in grams * 1 Mol H20) / (atomic mass of H20g) atomic mass found by using periodic table 3: Now we have the number of H20 moles so we can use Avogadro's Number (molecules/moles) to convert moles to molecules by mult...
by hannahtweedy
Thu Apr 05, 2018 10:21 am
Forum: Limiting Reactant Calculations
Topic: Module 3: Limiting Reactant Calculations, Question 19
Replies: 4
Views: 273

Re: Module 3: Limiting Reactant Calculations, Question 19

Jocelyn is right, you can't do anything with this problem without balancing the equation first to make sure to account for the Law of Conservation of Mass. The next step would be calculating the number of moles that are actually given from the mass in grams. Use this information to determine which i...
by hannahtweedy
Tue Apr 03, 2018 1:06 pm
Forum: Student Social/Study Group
Topic: Study Group
Replies: 10
Views: 644

Study Group

Hi everybody! My name is Hannah. A few of us are starting a weekly chemistry study group Thursdays at 4:30-6:30 at Sproul Hall. Depending on availability, we'll meet in a lounge or one of the study rooms - either way, we'll meet in the lobby. I'll post again if there are any changes to the informati...

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