Search found 20 matches

by Christopher Liu 3J
Sat Mar 18, 2017 7:18 pm
Forum: *Cyclohexanes (Chair, Boat, Geometric Isomers)
Topic: Boat conformation
Replies: 1
Views: 434

Re: Boat conformation

Yes, boat conformation has axial and equatorial positioning.
by Christopher Liu 3J
Wed Mar 15, 2017 5:18 pm
Forum: *Chem3D
Topic: Dynamic Molecules
Replies: 1
Views: 421

Re: Dynamic Molecules

All that means is that the molecules are constantly switching conformations i.e. they are not stagnant.
by Christopher Liu 3J
Wed Mar 15, 2017 5:15 pm
Forum: *Cyclohexanes (Chair, Boat, Geometric Isomers)
Topic: Eclipsed Hydrogens for Boat Conformation of Cyclohexanes
Replies: 1
Views: 236

Re: Eclipsed Hydrogens for Boat Conformation of Cyclohexanes

I assume it's talking about the "square" of carbons and its hydrogens. So, it would be the bottom four carbons. If you look down each pair of carbons, you will see they have two eclipsed hydrogen atoms in this formation, resulting in a total of four.
by Christopher Liu 3J
Wed Mar 15, 2017 5:08 pm
Forum: *Haloalkenes
Topic: Which gets priority in naming?
Replies: 1
Views: 467

Re: Which gets priority in naming?

Yes, the order is:
(1) Functional Groups (chlorides are considered substituents)
(2) Double/Triple Bonds
(3) Substituents
by Christopher Liu 3J
Wed Mar 15, 2017 5:07 pm
Forum: *Cyclohexanes (Chair, Boat, Geometric Isomers)
Topic: Cyclohexane conformation
Replies: 1
Views: 255

Re: Cyclohexane conformation

The molecules are constantly in motion (outside of 0K) and when molecules collide, some energy is transferred. This energy causes the chair confirmation to go into boat confirmation and subsequently back into chair confirmation instantaneously.
by Christopher Liu 3J
Thu Mar 09, 2017 9:13 pm
Forum: *Alkanes
Topic: Homework question
Replies: 1
Views: 212

Re: Homework question

First, your original answer should be 2, 2, 3-trimethyl-5-pentene. 2-pentene is not possible based on the numbering. As to why it's 334 is because double and triple bonds get higher priority in receiving lower numbering when compared to substituents. This means that you should always give the lowest...
by Christopher Liu 3J
Wed Feb 15, 2017 9:53 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: standard cell potential at equilibrium
Replies: 1
Views: 197

Re: standard cell potential at equilibrium

Log(k)=(nEo)/.0592
The equation comes from the nernst equation. At equilibrium, E=0, so you can rearrange it to this form. Also, this form assumes 25 Celsius. Use the more generalized equation if not at this temperature.
by Christopher Liu 3J
Sun Feb 05, 2017 4:16 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Standard Potentials in Electrochemical Series
Replies: 1
Views: 165

Re: Standard Potentials in Electrochemical Series

Standard potential can be thought of as the electron pulling power of an electrode. So, if the standard potential is a large positive number, it has a greater ability of pulling electrons towards itself, making it a strong oxidizer. Therefore a negative standard potential is essentially saying the e...
by Christopher Liu 3J
Mon Jan 16, 2017 11:59 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Problem 8.57 (Hess's Law)
Replies: 2
Views: 338

Re: Problem 8.57 (Hess's Law)

Remember that Hess' Law is essentially just the ability to add together reactions (and their standard enthalpy values) in order to create the original equation given and the enthalpy of reaction. Number 57 wants the reaction enthalpy of C 2 H 2 (g) + 2H 2 (g) \rightarrow C 2 H 6 (...
by Christopher Liu 3J
Fri Jan 13, 2017 12:29 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Most Stable Form
Replies: 4
Views: 704

Re: Most Stable Form

There are more; for example, carbon's most stable form is graphite, or C(gr). Every element has a stable form, so I don't think we're expected to memorize all of them. I believe we'll be given a table of the ones we will use. If not, Lavelle will tell us which one's to memorize.
by Christopher Liu 3J
Fri Jan 13, 2017 12:07 am
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Heating Curve
Replies: 1
Views: 250

Re: Heating Curve

That energy added at those points is used to break intermolecular bonds rather than be used to increase the temperature of the substance; this is what's known as heat of fusion for changing from solid to liquid and heat of vaporization. The slope changes between some parts of the graph because of di...
by Christopher Liu 3J
Thu Jan 12, 2017 9:57 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: State Property/Function
Replies: 3
Views: 306

Re: State Property/Function

Yup, what Stephanie said sounds right considering state properties only take into account the initial and final values.
by Christopher Liu 3J
Thu Jan 12, 2017 9:39 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: State Property/Function
Replies: 3
Views: 306

Re: State Property/Function

State functions being path independent means that value will be the same regardless of how you got to that specific value. An example would be enthalpy or q p . Remember that enthalpy is the amount of heat released/absorbed at a constant pressure. If I want to melt 1 gram of ice that initially is at...
by Christopher Liu 3J
Thu Dec 01, 2016 9:34 pm
Forum: *Making Buffers & Calculating Buffer pH (Henderson-Hasselbalch Equation)
Topic: 13.5 [ENDORSED]
Replies: 2
Views: 392

Re: 13.5 [ENDORSED]

I also believe the book has an incorrect answer for 13.5a. The book states that the K a value for HCN is 4.9x10 -10 whereas both the course reader and online sources state that it should be ~6.2x10 -10 . The answer for the problem should be 7.8x10 -10 mol/L. EDIT: In fact, if a problem includes the ...
by Christopher Liu 3J
Tue Nov 29, 2016 7:11 pm
Forum: Bronsted Acids & Bases
Topic: Textbook Q12.9c
Replies: 1
Views: 295

Re: Textbook Q12.9c

My best guess is that NH2 is being transferred to the formed acetate ion and NH2 is not considered a proton. The proton and hydroxide ion is used to create H2O.
by Christopher Liu 3J
Sat Oct 29, 2016 6:02 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Energy Levels
Replies: 1
Views: 229

Re: Electron Energy Levels

Are you talking about quantum numbers (n,l,ml,ms) or are you just talking about energy levels (specifically hydrogen's electron being excited to a certain n value)? I assume you mean quantum numbers. Quantum numbers are like a unique tag for each electron; no two electrons in an atom can have the sa...
by Christopher Liu 3J
Sat Oct 22, 2016 3:31 pm
Forum: Electronegativity
Topic: Chap 2 Q 67
Replies: 2
Views: 369

Re: Chap 2 Q 67

Nitrogen has a half-filled 2p orbital, making it stable because of symmetry. Carbon is one electron short of having this somewhat stable structure, so is more willing to receive an electron, i.e. has a higher electron affinity.
by Christopher Liu 3J
Sun Oct 16, 2016 12:32 am
Forum: Ionic & Covalent Bonds
Topic: Question on Ionic vs Covalent bonds
Replies: 2
Views: 432

Re: Question on Ionic vs Covalent bonds

Yes, the general rule of thumb is that ionic bonds are formed between metal and nonmetal atoms while covalent bonds are formed between nonmetal atoms, but remember that the thing that actually determines bond type is the difference between electronegativity charges between the two atoms in question....
by Christopher Liu 3J
Fri Oct 07, 2016 11:31 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Purpose of Plank's constant in Bohr Equation [ENDORSED]
Replies: 1
Views: 287

Re: Purpose of Plank's constant in Bohr Equation [ENDORSED]

Planck's constant is needed when finding the energy of the radiation emitted/absorbed. The problem would essentially have to give you both final and initial energy levels and just ask you to find something like energy, wavelength, frequency, etc. for you to need to plug in the constant's value.
by Christopher Liu 3J
Wed Sep 28, 2016 2:38 pm
Forum: Properties of Light
Topic: Magnetic and Electric fields
Replies: 4
Views: 427

Re: Magnetic and Electric fields

I do have a question about the two fields though. When referring to the frequency of light, is that frequnecy about the cycles of the electric field or the cycles of the magnetic field? Or does it refer to both?

Go to advanced search