Search found 27 matches

by Rebecca Chu 1C
Thu Jun 14, 2018 11:55 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Charge on ligands? [ENDORSED]
Replies: 2
Views: 173

Charge on ligands? [ENDORSED]

How do you find the charge on ligands and the oxidation # if you're only given the overall charge of the molecule. I thought you needed to know both the overall charge and charge on all ligands to find the oxidation #.
by Rebecca Chu 1C
Mon Jun 11, 2018 4:56 pm
Forum: Ionic & Covalent Bonds
Topic: Test 3 Q7
Replies: 3
Views: 140

Test 3 Q7

It asks to circle which compound has the highest ionic character and the compounds were KBr or NaBr. Why does KBr have a more ionic character than NaBr? I circled NaBr because I thought Na has a higher electronegativity than K so NaBr has a higher ionic character, but I got it wrong.
by Rebecca Chu 1C
Sun Jun 03, 2018 11:35 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: 4 ligands shape?
Replies: 6
Views: 169

4 ligands shape?

I know 4 ligands can either be a tetrahedron or square planar, but how am I supposed to tell which shape is which when there are 4 ligands?
by Rebecca Chu 1C
Sun Jun 03, 2018 3:26 pm
Forum: Lewis Structures
Topic: Phosphate Lewis structure?
Replies: 4
Views: 179

Re: Phosphate Lewis structure?

Why doesn't the central atom follow the octet rule though?
by Rebecca Chu 1C
Sun Jun 03, 2018 3:04 pm
Forum: Lewis Structures
Topic: Phosphate Lewis structure?
Replies: 4
Views: 179

Phosphate Lewis structure?

This is a question from test 3. What would the correct lewis structure for a phosphate molecule be?
by Rebecca Chu 1C
Sun May 27, 2018 9:17 pm
Forum: Ionic & Covalent Bonds
Topic: Partial charge or full charge
Replies: 4
Views: 400

Partial charge or full charge

How do I tell whether an atom in a molecule has a partial positive/negative charge or a full positive/negative charge?
by Rebecca Chu 1C
Sun May 27, 2018 8:42 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Double bond
Replies: 5
Views: 264

Re: Double bond

You look at the size of the atoms. Smaller atoms that have small radius (and in turn, shorter bond length) will have a stronger bond and therefore, be shorter. And if one of the molecules has resonance structures, the double bond would be longer on the molecule with resonance structures.
by Rebecca Chu 1C
Sun May 27, 2018 4:19 pm
Forum: Lewis Structures
Topic: Central atom and octet rule?
Replies: 12
Views: 497

Central atom and octet rule?

Does the central atom have to follow the octet rule? I noticed in some lewis structures the central atom doesn't always have an octet.
by Rebecca Chu 1C
Sun May 20, 2018 10:51 pm
Forum: Dipole Moments
Topic: Meaning of a dipole
Replies: 7
Views: 177

Re: Meaning of a dipole

Vivian Gonzalez 1A wrote:A dipole is a separation of opposite electrical charges. The larger the difference in electronegativity, the greater the dipole moment.


So if there is a greater dipole moment, does the molecule have a stronger ionic bond? And is its potential energy greater?
by Rebecca Chu 1C
Sun May 20, 2018 10:46 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge Shortcut
Replies: 3
Views: 264

Formal Charge Shortcut

My TA said there was a shortcut she uses for calculating formal charge. (I have Rosie.) Does anyone know what it is? I didn't write down the shortcut.
by Rebecca Chu 1C
Sun May 20, 2018 10:42 pm
Forum: Ionic & Covalent Bonds
Topic: Covalent Character?
Replies: 3
Views: 150

Covalent Character?

Okay so I know that ionic bonds exhibit covalent character, but what exactly is the covalent character that it exhibits? And what constitutes a bond with a "more covalent character" than another? Also, if an ionic bond exhibits a covalent character, how do I differentiate whether a bond is...
by Rebecca Chu 1C
Sun May 20, 2018 10:35 pm
Forum: Lewis Acids & Bases
Topic: Lewis acid vs. base
Replies: 5
Views: 167

Lewis acid vs. base

How am I supposed to distinguish a Lewis acid from a Lewis base if I'm given a molecule?
by Rebecca Chu 1C
Sun May 06, 2018 11:09 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Energy difference between 4s and 3d
Replies: 3
Views: 155

Re: Energy difference between 4s and 3d

So is that specific only to the 3d and 4s orbitals or does the d subshell have lower energy than the s subshell that precedes it in general (i.e. will 4d have a higher energy level than 5s, etc.)?
by Rebecca Chu 1C
Sun May 06, 2018 10:29 pm
Forum: Molarity, Solutions, Dilutions
Topic: test 1
Replies: 1
Views: 140

Re: test 1

When I asked my TA, she said the solutions usually aren't posted and you can just ask questions from the test on Chemistry Community.
by Rebecca Chu 1C
Sun May 06, 2018 10:27 pm
Forum: Empirical & Molecular Formulas
Topic: test 1, question 7
Replies: 2
Views: 244

Re: test 1, question 7

An organic compound contains C and H so you know your empirical formula will be C_{x}H_{y} (because we don't know what x and y are yet). And then you are given grams of carbon dioxide which you can use to find the moles of C. You do the same thing with water (i.e. find moles of H) Basically: 69.4 g ...
by Rebecca Chu 1C
Sun Apr 29, 2018 11:17 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Parallel vs Paired Electrons
Replies: 2
Views: 97

Parallel vs Paired Electrons

What does it mean when 2 electrons are parallel? And what does it mean when 2 electrons are paired?
by Rebecca Chu 1C
Sun Apr 29, 2018 11:11 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Nodes
Replies: 2
Views: 65

Nodes

Difference between angular node and radial node?
by Rebecca Chu 1C
Sun Apr 29, 2018 11:05 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Radius
Replies: 3
Views: 94

Re: Radius

I don't think atoms of different elements can have the same atomic radius so if the radius of an atom changes, you're probably dealing with a different atom that you initially were.

(NOT ENTIRELY SURE ABOUT THIS, BUT IF I AM WRONG, PLEASE CORRECT ME)
by Rebecca Chu 1C
Sun Apr 22, 2018 9:08 pm
Forum: Properties of Light
Topic: Interference [ENDORSED]
Replies: 3
Views: 107

Re: Interference [ENDORSED]

I hope this visual helps a little bit.

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by Rebecca Chu 1C
Sun Apr 22, 2018 8:57 pm
Forum: DeBroglie Equation
Topic: Week 3 discussion, question 6 [ENDORSED]
Replies: 2
Views: 109

Re: Week 3 discussion, question 6 [ENDORSED]

First, you have convert 4.37 eV to J so you have 4.37 eV x [(1.602 x 10^-19 J)/1 eV] = 7.0 x 10^-19 J. It also tells you that this is your work function so this is your \Phi You should also convert v = 1.5 x 10^3 km/s to 1.5 x 10^6 m/s since we will be working with Joules. Then you use KE = \frac{1}...
by Rebecca Chu 1C
Sun Apr 22, 2018 8:20 pm
Forum: Photoelectric Effect
Topic: hw 1.23 [ENDORSED]
Replies: 3
Views: 106

Re: hw 1.23 [ENDORSED]

1 keV = 1.602 x 10^-16 J so you use dimensional analysis to convert keV to Joules.
140.511 keV x [(1.602 x 10^-16) J / 1 keV] = 2.251 x 10^-14
by Rebecca Chu 1C
Sun Apr 15, 2018 9:57 pm
Forum: Properties of Electrons
Topic: Photoelectric Effect and its light intensity [ENDORSED]
Replies: 2
Views: 108

Photoelectric Effect and its light intensity [ENDORSED]

Why doesn't the photoelectric effect work in with high intensity light? Why must it be a light source with a long wavelength? What does a long wavelength do to the electrons that a short wavelength can't do in the photoelectric effect?
by Rebecca Chu 1C
Sun Apr 15, 2018 9:53 pm
Forum: Properties of Light
Topic: How do I use Planck's constant? [ENDORSED]
Replies: 4
Views: 160

Re: How do I use Planck's constant? [ENDORSED]

Planck's constant is used to calculate the energy of one photon in a wavelength. (Dr. Lavelle showed us an example where we use Planck's constant in Friday's lecture.)
by Rebecca Chu 1C
Sun Apr 15, 2018 9:47 pm
Forum: SI Units, Unit Conversions
Topic: Quiz 1
Replies: 6
Views: 287

Re: Quiz 1

The empirical formula expresses the atoms in a molecule/compound in terms of ratios. The molecular formula shows the actual number of atoms in a molecule/compound. Some molecules can have the same empirical formula (e.g. glucose and acetic acid both have the empirical formula of CH_{2}O but glucose ...
by Rebecca Chu 1C
Sun Apr 15, 2018 9:33 pm
Forum: Properties of Light
Topic: Difference between wave model and particle model? [ENDORSED]
Replies: 6
Views: 1904

Difference between wave model and particle model? [ENDORSED]

What exactly is the difference between the wave model and particle model?
by Rebecca Chu 1C
Sun Apr 15, 2018 9:26 pm
Forum: Photoelectric Effect
Topic: Photoelectric Effect
Replies: 2
Views: 58

Photoelectric Effect

Does anyone know why only one photon affects only one electron? Why can't multiple photons affects one electron?
by Rebecca Chu 1C
Mon Apr 09, 2018 7:22 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Homework Question E9a
Replies: 2
Views: 198

Homework Question E9a

"Epsom salts consist of magnesium sulfate heptahydrate. Write its formula. (a) How many atoms of oxygen are in 5.15 g of Epsom salts?" I referred to the solutions manual while solving for the atoms of O. It used 11 mol O atoms in the dimensional analysis, but I'm confused why it isn't just...

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