Search found 23 matches

by Wesley Shen Lec 4
Fri Mar 04, 2016 12:02 pm
Forum: *Alkanes and Substituted Alkanes (Staggered, Eclipsed, Gauche, Anti, Newman Projections)
Topic: Drawing Structures
Replies: 2
Views: 318

Re: Drawing Structures

When drawing trans and cis models, I just draw the line structures first, then make sure the substituents are on the same or opposite sides accordingly.
by Wesley Shen Lec 4
Wed Feb 24, 2016 4:02 pm
Forum: *Alkanes
Topic: Double bond of an alkene
Replies: 3
Views: 506

Re: Double bond of an alkene

The pi bonds are on a different plane than the sigma bonds, as it is above and below. These regions are nucleophilic and have less overlap than sigma bonds, so they will be the electrons that are lost.
by Wesley Shen Lec 4
Wed Feb 24, 2016 4:00 pm
Forum: *Alkanes
Topic: Double or Triple Bond as substituents
Replies: 1
Views: 217

Re: Double or Triple Bond as substituents

When dealing with alkanes (saturated hydrocarbons), each carbon should have a hybridization of sp3. So a carbon with a double bond substituent wouldn't be considered an alkane. Correct me if I'm wrong.
by Wesley Shen Lec 4
Thu Feb 18, 2016 3:07 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Units of T
Replies: 2
Views: 370

Re: Units of T

Since you will be plugging in time in integrated rate laws that use the natural log, when you solve for T the units will cancel and time should just be in the units that you've plugged it in for. For example, for a 1st order reaction half life the equation is .693/k, and the time units don't get can...
by Wesley Shen Lec 4
Thu Feb 18, 2016 3:05 pm
Forum: General Rate Laws
Topic: k' confusion
Replies: 2
Views: 465

Re: k' confusion

Since k depends on temperature (and other factors such as pseudo rate laws), k' is just used to differentiate between the different ones.
by Wesley Shen Lec 4
Mon Feb 08, 2016 8:36 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: equations
Replies: 2
Views: 487

Re: equations

In the Course Reader, how does he get from the RT/nF to 2.303RT/F @ 25 degrees celsius to .0592/n?
by Wesley Shen Lec 4
Wed Feb 03, 2016 11:38 am
Forum: Balancing Redox Reactions
Topic: Add H+ or OH-
Replies: 5
Views: 2588

Re: Add H+ or OH-

For redox reactions in basic solution, proceed as you would as if in an acidic solution. Balance O with H20 and the H with H+. Now consider that we are in a basic solution, and add the same number of OH- ions on both sides of the reaction to balance out the H+.
by Wesley Shen Lec 4
Tue Feb 02, 2016 8:28 pm
Forum: Balancing Redox Reactions
Topic: HW Problem 5 A.
Replies: 1
Views: 222

HW Problem 5 A.

One of the equations is O3 changes into O2. Since the O has an oxidation number of 0 since its a neutral molecule, is this considered the reduction or oxidation part of the reaction?
by Wesley Shen Lec 4
Mon Jan 25, 2016 11:23 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Isothermal
Replies: 3
Views: 464

Re: Isothermal

You're confusing temperature (T) with enthalpy (Delta H). Temperature is the measure of random motion, while the enthalpy is the heat given off by a chemical reaction at standard pressure.
by Wesley Shen Lec 4
Sun Jan 17, 2016 11:27 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Reversible and Irreversible Reactions Definition
Replies: 3
Views: 960

Re: Reversible and Irreversible Reactions Definition

The book states that the work a system can do is greatest in a reversible process.
What does it mean by that?
by Wesley Shen Lec 4
Sun Jan 10, 2016 6:59 pm
Forum: Phase Changes & Related Calculations
Topic: Example in course reader
Replies: 2
Views: 319

Re: Example in course reader

Two compounds coming together doesn't necessarily have to be endothermic or exothermic. The change in enthalpy can be calculated several ways as outlined in the course reader. One way is using bond enthalpies: add up the energy required to break all the bonds of the reactants and add the energy rele...
by Wesley Shen Lec 4
Thu Dec 03, 2015 11:55 pm
Forum: *Biological Importance of Buffer Solutions
Topic: Buffer solutions and salt
Replies: 2
Views: 1010

Re: Buffer solutions and salt

I think the salt stabilizes the otherwise unstable conjugate aid or base with a charge so that it can be stored and administered.
by Wesley Shen Lec 4
Sun Nov 15, 2015 6:12 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Ligand Definition and Coordination Number
Replies: 2
Views: 807

Re: Ligand Definition and Coordination Number

Coordination number is the number of bonds that the metal ion has. So in cases of polydentate ligands, each bond contributes to coordination number. Two bidentate ligands will result in an coordination number of 4.
by Wesley Shen Lec 4
Sun Nov 15, 2015 6:04 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: How to determine monodentate or bidentate?
Replies: 3
Views: 3867

Re: How to determine monodentate or bidentate?

in H20, there is only one atom with lone pairs, which is O. Even though it has two lone pairs it can only bind to the metal in one place because its only one O atom. In CO2, there are two O atoms, each of which has lone pairs, so there are two potential sites where the molecule can bind to the metal...
by Wesley Shen Lec 4
Sun Nov 15, 2015 4:33 pm
Forum: Naming
Topic: Naming Complex Anions
Replies: 1
Views: 344

Re: Naming Complex Anions

Whenever the ion is a cation (negative charge), add ate to the end of the ion name. So in this case, it would be the first name, cuprate, rather than copper.
by Wesley Shen Lec 4
Mon Nov 02, 2015 7:23 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: MO for molecules with more than one element
Replies: 3
Views: 403

Re: MO for molecules with more than one element

In cases like these, will the pi bonding orbitals be lower than than the sigma bonding orbitals for 2p? What if one atom has a nuclear charge of less than 8 and the other one a charge of over 8?
by Wesley Shen Lec 4
Mon Oct 26, 2015 12:35 am
Forum: Determining Molecular Shape (VSEPR)
Topic: central atom for ClO2+
Replies: 2
Views: 500

Re: HW Question 4.5

I don't think an O in the center single bonded and double bonded to another O has lower formal charges.. The Cl would have a charge of 0, the central O would have +1, and the other O would have 0. The molecule with Cl as the central atom would have both O with a formal charge 0 and Cl with a +1. As ...
by Wesley Shen Lec 4
Mon Oct 19, 2015 8:37 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge on Central Atom
Replies: 1
Views: 1122

Formal Charge on Central Atom

So on Chapter 3 Problem 57. c., it asks us to draw out possible Lewis Structures for the perchlorate ion, CLO4-. The answer the solutions manual gives is it's a resonance structure with 3 triple bonds between Cl and O and one single bond between Cl and the remaining O, because this gives us a formal...
by Wesley Shen Lec 4
Tue Oct 13, 2015 11:54 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Shielding Electrons 2.37b
Replies: 2
Views: 562

Re: Shielding Electrons 2.37b

When an orbital has "penetrating abilities", that just means it can get closer to the nucleus. S orbitals have penetrating abilities, which is why a 4s orbital will fill up before a 3d orbital, even though it has a higher principal quantum number and is technically a higher energy level. I...
by Wesley Shen Lec 4
Tue Oct 13, 2015 11:18 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Delta x
Replies: 4
Views: 1658

Re: Delta x

Delta x just refers to the uncertainty in position. If you are given the radius, you don't necessarily need to multiply by 2, you just take it how the problem is posed. If we are given that an electron is confined within the nucleus, then it's delta x would be the diameter of the nucleus, for it cou...
by Wesley Shen Lec 4
Sun Oct 11, 2015 6:22 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Shielding Effect
Replies: 5
Views: 959

Re: Shielding Effect

I think Dr. Lavelle explained it like this: When the electron is infinitely far from the nucleus, the energy of the electron is 0 because it is not interacting with the nucleus. So if we take 0 as our reference state, as we get closer and closer to the nucleus, the electron goes into a lower and low...
by Wesley Shen Lec 4
Mon Oct 05, 2015 1:06 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Hydrogen Atom Spectroscopy Series
Replies: 1
Views: 252

Hydrogen Atom Spectroscopy Series

So for question 1.11, the book explained the answer as "In each of these series, the principal quantum number for the lower energy level involved is the same for each absorption line." Just to clarify, for the Lyman series, does that mean that the electron excited HAS to begin in the energ...
by Wesley Shen Lec 4
Sat Oct 03, 2015 9:05 pm
Forum: Properties of Light
Topic: Relationship between frequency and wavelength
Replies: 7
Views: 1520

Re: Relationship between frequency and wavelength

All electromagnetic radiation travel at the speed of light, which is c= 3.0 x 10^8 m/s. Therefore, you can interpret this as they travel the same distance over the same time. If the wavelength is longer, less cycles of a wave will pass through a given distance over a given time. In other words, if y...

Go to advanced search