Search found 34 matches
- Sat Mar 18, 2017 11:29 am
- Forum: *Alkenes
- Topic: Cis and Trans
- Replies: 2
- Views: 1389
Cis and Trans
Is it possible to have more than one cis and trans configuration in one molecule (resulting from multiple double bonds)? If so, how would we go about naming such a molecule?
- Fri Mar 17, 2017 10:11 pm
- Forum: *Alkanes
- Topic: Course Reader Page 94
- Replies: 1
- Views: 2836
Course Reader Page 94
On page 94 in the course reader, I am a bit confused on the labeling and was wondering what we need to know. I can see iso, neo, vinyl, and allyl, but what exactly is the structure of an amyl or isoamyl? I apologize if I am just not seeing somethign that is obvious. Thank you in advance!
- Tue Mar 07, 2017 8:41 pm
- Forum: *Nucleophiles
- Topic: Nucleophilic Strength Guidelines
- Replies: 1
- Views: 1252
Nucleophilic Strength Guidelines
What are the general guidelines/rules for determining nucleophilic strength? Electrophilic strength? The textbook notes some rules, but it also says that the rules are not definitive so I am a bit confused. Thank you in advance!
- Fri Mar 03, 2017 1:50 am
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Steady State vs. Pre-Equilibrium Approach
- Replies: 2
- Views: 977
Steady State vs. Pre-Equilibrium Approach
What exactly are the differences between the steady-state and pre-Equilibrium approaches (and any others I may have excluded)? What are the differences conceptually and when would we use each? Thanks in advance!
- Thu Feb 23, 2017 10:25 am
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: Homework Question 15.23
- Replies: 1
- Views: 456
Homework Question 15.23
After finding the concentration of A via the concentration of B, why is the following step done?
[A]0 - [(2 mol A/1 mol B)*(0.034 mol B/L)]
Thanks in advance.
[A]0 - [(2 mol A/1 mol B)*(0.034 mol B/L)]
Thanks in advance.
- Sat Feb 18, 2017 5:51 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagrams [ENDORSED]
- Replies: 3
- Views: 698
Cell Diagrams [ENDORSED]
Why is there sometimes a random metal added to the cell diagram notation when it wasn't involved in the reaction given (ex: Pt, Cd, etc)? Thanks in advance!
- Mon Feb 13, 2017 5:29 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidation Number of Diatomic Oxygen
- Replies: 2
- Views: 1506
Oxidation Number of Diatomic Oxygen
Would the Oxidation number for diatomic Oxygen (O2) be 0 because it's a the common form molecule or -2 as in usual cases (besides in peroxide)?
- Thu Feb 09, 2017 1:00 am
- Forum: Balancing Redox Reactions
- Topic: General Guidelines for Writing Half Reactions
- Replies: 1
- Views: 450
General Guidelines for Writing Half Reactions
What exactly are the general guidelines for writing the half reactions to determine E (standard) of the cell? Also, why is the half reaction method recommended over the use of the equation E (standard) cell= E (standard) cathode- E (standard) anode? Thanks in advance!
- Wed Feb 01, 2017 3:51 pm
- Forum: Calculating Work of Expansion
- Topic: Sign of Work
- Replies: 4
- Views: 1052
Sign of Work
When is work positive or negative in terms of thermodynamics? When the system is doing work (what sign)? When work is done on the system (what sign)?
- Thu Jan 26, 2017 7:02 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Degeneracy
- Replies: 11
- Views: 853
Degeneracy
What exactly is degeneracy conceptually? How is it applied in thermodynamics?
- Thu Jan 26, 2017 7:00 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Reversible Reaction
- Replies: 1
- Views: 407
Reversible Reaction
What exactly does it mean when a reaction is reversible? Thank you in advance.
- Thu Jan 19, 2017 10:22 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Cv vs Cp
- Replies: 1
- Views: 353
Cv vs Cp
What exactly is the difference between c, Cv, and Cp? When would each be used and why are the three different designations necessary? Thanks in advance!
- Thu Jan 12, 2017 10:22 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Standard Enthalpy of Formation Question
- Replies: 3
- Views: 700
Standard Enthalpy of Formation Question
I had a question on standard enthalpy of formation discussed in class. What exactly is it? Dr. Lavelle mentioned that for some molecules, the standard enthalpy of formation is 0 and thus we cannot find the value on a chart (ex: diatomic hydrogen; H2). Why exactly is this so? Thank you in advance!
- Sat Dec 03, 2016 6:01 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Acid/Base Problem Estimation Method
- Replies: 1
- Views: 519
Acid/Base Problem Estimation Method
On the final, are we allowed to use the estimation method Dr. Lavelle mentioned in class (where we ignore x in the denominator if presumed to be small and less than 5% of the concentration given) on the final?
- Fri Dec 02, 2016 2:13 am
- Forum: Conjugate Acids & Bases
- Topic: Weak Acid/Base-Strong Base/Acid Titration Question
- Replies: 1
- Views: 464
Weak Acid/Base-Strong Base/Acid Titration Question
I had the following question in regards to what Dr. Lavelle mentioned in lecture on the Weak Acid/Base-Strong Base/Acid Titrations section of the course reader. He said that we could use a memory tool of: Weak Acid + Strong Base leads to a slightly more basic (slightly above pH 7) stoichiometric poi...
- Tue Nov 22, 2016 2:38 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Course Reader pg. 156-157
- Replies: 1
- Views: 432
Course Reader pg. 156-157
I had a question regarding the content in the course reader pages 156-157. I'm confused on what Dr. Lavelle meant when he was using the approximation method and saying that after you get a final value, this value can be misleading as you have to keep in mind that the pH of pure water is 10^-7. What ...
- Wed Nov 16, 2016 10:26 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: MO Energy Diagrams for non-diamtomics
- Replies: 1
- Views: 443
MO Energy Diagrams for non-diamtomics
How do we draw the the molecular orbital diagrams for hetero-nuclear molecules (i.e. HF, CO, NO)? Because one of the atoms is Z<8 and the other Z>8, do we put the pi 2p or sigma 2p above or below? How do we know which one it behaves like?
- Wed Nov 16, 2016 9:53 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: How to determine which orbital has less energy when drawing an MO Energy Diagram
- Replies: 2
- Views: 611
How to determine which orbital has less energy when drawing an MO Energy Diagram
I was wondering how you determine which orbital is less energy when drawing a molecular orbital energy diagram (i.e. N 2s vs. O 2s)? Thank you in advance.
- Wed Nov 16, 2016 3:22 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Kc vs Kp vs Q [ENDORSED]
- Replies: 1
- Views: 7044
Kc vs Kp vs Q [ENDORSED]
What exactly are the conceptual differences between Kc, Kp, and Q? When would you use each of them? Also conceptually, how does comparing Kc or Kp to Q equate to determining which direction a reaction is favored? Thank you in advance.
- Thu Nov 10, 2016 12:46 am
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: HOMO to LUMO Concept
- Replies: 3
- Views: 1096
HOMO to LUMO Concept
I had the following question:
What exactly does the concept of HOMO (highest occupied molecular orbital) to LUMO (lowest unoccupied molecular orbital) refer to? What does the acronym tell us?
Thank you in advance.
What exactly does the concept of HOMO (highest occupied molecular orbital) to LUMO (lowest unoccupied molecular orbital) refer to? What does the acronym tell us?
Thank you in advance.
- Wed Nov 02, 2016 9:31 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Bonding vs. Anti-bonding
- Replies: 2
- Views: 2558
Bonding vs. Anti-bonding
What exactly does bonding and anti-bonding mean/refer to? I am a bit confused on what they mean and how to determine which electrons are in the bonding molecular orbital and anti-bonding molecular orbital. Thanks in advance.
- Wed Nov 02, 2016 9:30 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: How to Fill Out a Molecular Orbital Energy Level Diagram
- Replies: 2
- Views: 1790
How to Fill Out a Molecular Orbital Energy Level Diagram
I know that this might be hard to put into words, but what are the general rules on filling out a Molecular Orbital Energy Level Diagram (i.e. how to fill in electrons into bonding/antibonding orbitals, how to determine which is bonding/antibonding, etc.)?
- Tue Oct 25, 2016 3:24 pm
- Forum: Lewis Structures
- Topic: Lewis Structure Octet Rule Exceptions
- Replies: 4
- Views: 929
Lewis Structure Octet Rule Exceptions
I understand that the Lewis Structures depend on formal charge and octet rule (with formal charge being more important), but I had the following question: Which elements tend to be/can be octet exceptions (example Boron can have 3 bonds as well as other elements with expanded octets)? Is there a way...
- Thu Oct 20, 2016 1:16 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: General Rules on Writing e- Configurations [ENDORSED]
- Replies: 2
- Views: 784
General Rules on Writing e- Configurations [ENDORSED]
I had the following question about writing electron configurations. I know during lecture Dr. Lavelle stated that once the d orbital becomes available for an element, the electron placement on the configuration short hand notation does not simply fill in order (i.e. [Ar] 4s^2 3d^3 vs. [Ar] 3d^5). I ...
- Fri Oct 14, 2016 3:56 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Rydberg Equation, Variations, and which n value to put first.
- Replies: 1
- Views: 687
Rydberg Equation, Variations, and which n value to put first.
I had the following question about the Rydberg Equation: So I know that there are variations of the same equation that can be derived: (frequency)= R( (1/(n1)^2)-(1/(n2)^2)) En=-((R)(h))/n^2 When would it be most efficient/beneficial to use each variation of the equation? Also how does one determine...
- Fri Oct 14, 2016 3:48 pm
- Forum: Trends in The Periodic Table
- Topic: Atomic Radius
- Replies: 2
- Views: 562
Re: Atomic Radius
I agree with the above reply. Basically, electrons are thought to be in orbitals and electron clouds which do not have a definite shape. Thus, because the electrons do not form a convenient circular shell (which we can easily find the radius of), we must average out the distance between what we can ...
- Fri Oct 14, 2016 3:45 pm
- Forum: Photoelectric Effect
- Topic: Threshold Energy Question
- Replies: 1
- Views: 518
Re: Threshold Energy Question
The first equation is used when an electron has not been ejected with an exit velocity off of the solid metal once the light source hits it. The second equation is used when the electrons have been ejected with a kinetic energy (which implies velocity). Basically, both equations are talking about th...
- Tue Oct 11, 2016 6:13 pm
- Forum: Significant Figures
- Topic: Sig fig with constants
- Replies: 2
- Views: 907
Re: Sig fig with constants
My TA said to just use as many significant figures as the constant you used. So depending on the value you used (i.e. speed of light=3.0*10^8 m/s as opposed to 2.998*10^8 m/s) in the problem. Thus, if you are using the constant on the equation sheet, he said to use as many significant figures as you...
- Thu Oct 06, 2016 2:38 pm
- Forum: Properties of Electrons
- Topic: Wavelike Properties? [ENDORSED]
- Replies: 2
- Views: 860
Re: Wavelike Properties? [ENDORSED]
I believe what that problem is trying to teach you is that when we try to describe macroscopic objects with quantum mechanical wave functions (which are meant for extremely small objects) the results are not really visible. If you look at de Broglie's wave equation λ= (h)/(mv) with your car example,...
- Thu Oct 06, 2016 2:17 pm
- Forum: Student Social/Study Group
- Topic: Dykstra Hall Study Group (Fall 2016)
- Replies: 25
- Views: 3522
Re: Dykstra Hall Study Group (Fall 2016)
Okay, I''ll be sure to add you guys to the Group Me sometime in the next day or two.
- Thu Sep 29, 2016 4:59 pm
- Forum: Photoelectric Effect
- Topic: Wave-Particle Duality and Equations Used
- Replies: 1
- Views: 453
Wave-Particle Duality and Equations Used
I'm a bit confused on the Wave-Particle Duality of light. So light behaves both as a wave AND particle (photon), and we don't know how to properly draw out a beam of light correct? In terms of the equations, my question is the following: So if equations such as c=(wavelength)*(frequency) describe li...
- Thu Sep 29, 2016 4:47 pm
- Forum: Student Social/Study Group
- Topic: Dykstra Hall Study Group (Fall 2016)
- Replies: 25
- Views: 3522
Re: Dykstra Hall Study Group (Fall 2016)
Okay, I just sent an email with everyone's email posted prior to this message. We could meet in the lounge or something (depending on how crowded). Could you guys message your phone numbers on the mass email so that we can get a convenient group chat started? The goal is probably to meet for the fir...
- Mon Sep 26, 2016 5:03 pm
- Forum: Student Social/Study Group
- Topic: Dykstra Hall Study Group (Fall 2016)
- Replies: 25
- Views: 3522
Re: Dykstra Hall Study Group (Fall 2016)
We could obviously take on more people, but I think that we definitely have enough to at least start forming a small group. Yeah if you guys could leave some form of contact (email, phone, Facebook, etc) I could form a group chat or something. And once we have everyone, we could meet on one of the l...
- Sun Sep 25, 2016 6:03 pm
- Forum: Student Social/Study Group
- Topic: Dykstra Hall Study Group (Fall 2016)
- Replies: 25
- Views: 3522
Dykstra Hall Study Group (Fall 2016)
If any of you guys are living in Dykstra Hall, let me know if you want to form a study group. Anyone not living in Dykstra is welcome as well (we could meet in a library).