Search found 24 matches

by Emily Li 4A
Sat Dec 01, 2018 10:08 pm
Forum: Dipole Moments
Topic: Dipole moments and resonances
Replies: 3
Views: 105

Re: Dipole moments and resonances

Is there a source where we can find all of the exceptions in one place?
by Emily Li 4A
Sat Dec 01, 2018 10:07 pm
Forum: Lewis Acids & Bases
Topic: Lewis/Bronsted acids and bases
Replies: 2
Views: 54

Re: Lewis/Bronsted acids and bases

There are two different definitions of acids and bases: 1) Lewis acid and base 2) Bronsted acid and base By definition, lewis acids and bases are defined in terms of being able to accept or donate electron pairs. In comparison, Bronsted acids and bases are defined in terms of being able to accept o...
by Emily Li 4A
Sat Dec 01, 2018 9:55 pm
Forum: Naming
Topic: With Respect to the Final
Replies: 9
Views: 211

Re: With Respect to the Final

I believe you have to know both, especially if such problems are on the homework.
by Emily Li 4A
Sun Nov 25, 2018 5:45 pm
Forum: Octet Exceptions
Topic: Radicals
Replies: 16
Views: 545

Re: Radicals

I remember doing a homework question where you have to draw the lewis structure of ClO. Since there are only 13 electrons available for the structure, I naturally thought that Cl had a full octet and O had only 7 electrons, with one electron by itself to show that ClO is a radical. However, the answ...
by Emily Li 4A
Sun Nov 25, 2018 5:37 pm
Forum: Trends in The Periodic Table
Topic: Ionization energy
Replies: 4
Views: 245

Re: Ionization energy

I usually visualize trends with the help of this table, which is very useful for questions like these:

https://upload.wikimedia.org/wikipedia/commons/f/fe/Periodic_trends.svg
by Emily Li 4A
Sun Nov 25, 2018 5:21 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Test 3
Replies: 38
Views: 758

Re: Test 3

DavidEcheverri3J wrote:Will we also need to know the degrees of the shapes?


I think it's very likely that we have to know them, but at least we can use simple math to find angles in most of the shapes.
by Emily Li 4A
Sun Nov 18, 2018 7:38 pm
Forum: Student Social/Study Group
Topic: Turning in Homework (Thanksgiving Break)
Replies: 8
Views: 243

Re: Turning in Homework (Thanksgiving Break)

I believe Lavelle sent out an email earlier this week answering this question on the forum somewhere.
by Emily Li 4A
Sun Nov 18, 2018 7:33 pm
Forum: Ionic & Covalent Bonds
Topic: Salts and Molecules
Replies: 2
Views: 99

Re: Salts and Molecules

I usually use a trick to connect the types of bonds to their characteristics. For example, when salts are placed in water they can easily dissolve into ions, hence they have "ionic" bonds. Covalent compounds have relatively opposing characteristics compared to ionic compounds; they don't e...
by Emily Li 4A
Sun Nov 18, 2018 7:25 pm
Forum: Bond Lengths & Energies
Topic: Lengths of different types of bonds
Replies: 3
Views: 93

Re: Lengths of different types of bonds

Generally, it would be assumed that the more bonds there are, the smaller the bond length is. This is not the case, however, with compounds with resonance structures. Each resonance structure would exist simultaneously in the compound (such as how a mule is a horse and a donkey at the same time) and...
by Emily Li 4A
Fri Nov 02, 2018 7:07 pm
Forum: Student Social/Study Group
Topic: Midterm
Replies: 15
Views: 443

Re: Midterm

Do we know how many questions from each section will be in the test? Like how many from the fundamentals, quantum, and chemical bonds? I know there’s 8 but how is it going to be divided? I believe the test will cover the three major units: Fundamentals, Chap 1 and Chap 2 (up to 2C), but it's really...
by Emily Li 4A
Fri Nov 02, 2018 6:59 pm
Forum: Lewis Structures
Topic: Double Bonds In Lewis Structures
Replies: 2
Views: 188

Re: Double Bonds In Lewis Structures

When drawing Lewis Structures, how do we know if we need to draw a double bond, and how do you determine which element gets the double bond? To elaborate on Joonsoo's post, formal charge is determined by the formula: FC=V-(L+S/2), where FC is formal charge, V is the number of valence electrons of t...
by Emily Li 4A
Fri Nov 02, 2018 6:40 pm
Forum: Lewis Structures
Topic: ch3 #5 6th edition
Replies: 1
Views: 50

Re: ch3 #5 6th edition

Give the ground-state electron configuration expected for each of the following ions: a) Cu+ b) Bi^3+ c) Ga^3+. d) Tl^3+ I know that you're supposed to use brackets with the element from the last column on the row above as a shortcut, but I'm confused on how to set up the rest of the configuration....
by Emily Li 4A
Thu Oct 25, 2018 9:38 pm
Forum: *Shrodinger Equation
Topic: Help on how to find l, ml, and ms
Replies: 6
Views: 1584

Re: Help on how to find l, ml, and ms

This is a review I made while studying for my test: >l is the orbital angular momentum quantum number >this changes based on the block (s,p,d, or f) >l=0 for the s block, 1 for the p block, 2 for d block, and 3 for f block >n is the principle quantum number, or energy level >increases in value by pe...
by Emily Li 4A
Thu Oct 25, 2018 9:31 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Heisenberg Indeterminacy Equation
Replies: 4
Views: 142

Re: Heisenberg Indeterminacy Equation

The formula is also related to the concept of complementarity, which relates location and momentum (if one is known, the other can not be known without a margin or error, or "uncertainty"). This formula helps us accurately depict the motions of particles; the smaller the particle, the larg...
by Emily Li 4A
Mon Oct 22, 2018 5:26 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Orientations of Orbitals
Replies: 1
Views: 49

Orientations of Orbitals

I was wondering if we need to memorize the orientations of the p, d, and f orbitals across the planes (i.e., one d-orbital is located along the z-axis and its donut is in the x-y plane). Is knowing the number of types for each orbital and what shapes they generally have enough?
by Emily Li 4A
Sat Oct 20, 2018 12:10 am
Forum: DeBroglie Equation
Topic: does everything have a wavelength
Replies: 10
Views: 377

Re: does everything have a wavelength

Does anyone have the car problem the Professor used in order to explain this? A 1.50 * 10^3 kg car is travelling at 27.0 m/s. What is the de Broglie wavelength of the car? Does the car have any detectable wavelike properties? wavelength= h/p = h/mv = (6.626 *10^34 Js)/(1500 kg) (27.0 m/s) = 1.64 * ...
by Emily Li 4A
Fri Oct 19, 2018 11:59 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Concentration
Replies: 2
Views: 302

Re: Concentration

To find the molar mass, you first have to find the amount of each element used in the chemical formula. There are 3 moles of calcium. Since phosphate is doubled, there are 2 moles of phosphorus and 8 moles of oxygen. Multiply each of these numbers to the respective element's molar mass on the period...
by Emily Li 4A
Fri Oct 19, 2018 11:53 pm
Forum: Photoelectric Effect
Topic: Significance of the photoelectric effect
Replies: 3
Views: 546

Re: Significance of the photoelectric effect

I believe the photoelectric effect's significance stems from showing how light rejects the traditional wave model, and how light is instead perceived as photons/quanta of energy . According to the wave model, if the amplitude increases then the intensity of the light wave should increase and eject m...
by Emily Li 4A
Thu Oct 11, 2018 11:24 pm
Forum: SI Units, Unit Conversions
Topic: Fahrenheit, Celsius, Kelvin
Replies: 3
Views: 164

Re: Fahrenheit, Celsius, Kelvin

I was actually reading an article about this a few weeks ago! The above reason is true; we've been using this system for so long that adopting the metric system would just cause a huge amount of confusion. If you think about it more, that confusion could also cause some economic problems (though on ...
by Emily Li 4A
Thu Oct 11, 2018 11:10 pm
Forum: SI Units, Unit Conversions
Topic: Rounding Off of 5
Replies: 7
Views: 261

Re: Rounding Off of 5

On Lavelle's site, there is a handy cheat sheet for sig figs if you're ever confused about them. They're under the Math Assistance section in "everything you want to know about significant figures" and "More Significant Figure Discussion". It covers everything in depth, including...
by Emily Li 4A
Thu Oct 11, 2018 11:04 pm
Forum: SI Units, Unit Conversions
Topic: Conversion
Replies: 6
Views: 215

Re: Conversion

I'm currently working on a homework problem and one of the steps is to convert meters to Joules. Does anyone know a quick conversion or a way to go from meters to Joules? It would really help me out. Thanks! Have you tried listing all of the available information in the problem and seeing if they c...
by Emily Li 4A
Thu Oct 04, 2018 4:27 pm
Forum: SI Units, Unit Conversions
Topic: Homework Questions [ENDORSED]
Replies: 14
Views: 279

Re: Homework Questions [ENDORSED]

Will homework always be due on Friday during the lecture? Or will we switch to turning in HW to the TA during our discussion period? Just wondering because what if we have to turn in homework that wasn't covered yet (in case our lecture is after our discussion period). I believe we need to turn in ...
by Emily Li 4A
Thu Oct 04, 2018 4:21 pm
Forum: Molarity, Solutions, Dilutions
Topic: Concentration- Calculating Volume
Replies: 4
Views: 97

Re: Concentration- Calculating Volume

For the beginning of these problems, I always find it helpful to write down new formulas (especially because it helps with my memory) without anything plugged into them. Alike to what Chem_Mod has said, doing this and finding what data is available helps you make a connection and forwards your probl...
by Emily Li 4A
Thu Oct 04, 2018 4:09 pm
Forum: Empirical & Molecular Formulas
Topic: Problem F.1b
Replies: 3
Views: 113

Re: Problem F.1b

This might be from applying significant figures to the calculations made before arriving at the answer. To have a more precise result, cut off the calculations you make to four decimal places and continue to do so until you arrive at the final answer. Then apply significant figures to the latter. Yo...

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