Search found 34 matches

by Junghyuk_Park_1I
Sat Mar 18, 2017 11:29 am
Forum: *Alkenes
Topic: Cis and Trans
Replies: 2
Views: 397

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?
by Junghyuk_Park_1I
Fri Mar 17, 2017 10:11 pm
Forum: *Alkanes
Topic: Course Reader Page 94
Replies: 1
Views: 349

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!
by Junghyuk_Park_1I
Tue Mar 07, 2017 8:41 pm
Forum: *Nucleophiles
Topic: Nucleophilic Strength Guidelines
Replies: 1
Views: 327

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!
by Junghyuk_Park_1I
Fri Mar 03, 2017 1:50 am
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Steady State vs. Pre-Equilibrium Approach
Replies: 2
Views: 519

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!
by Junghyuk_Park_1I
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: 191

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.
by Junghyuk_Park_1I
Sat Feb 18, 2017 5:51 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagrams [ENDORSED]
Replies: 3
Views: 330

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!
by Junghyuk_Park_1I
Mon Feb 13, 2017 5:29 pm
Forum: Balancing Redox Reactions
Topic: Oxidation Number of Diatomic Oxygen
Replies: 2
Views: 436

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)?
by Junghyuk_Park_1I
Thu Feb 09, 2017 1:00 am
Forum: Balancing Redox Reactions
Topic: General Guidelines for Writing Half Reactions
Replies: 1
Views: 224

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!
by Junghyuk_Park_1I
Wed Feb 01, 2017 3:51 pm
Forum: Calculating Work of Expansion
Topic: Sign of Work
Replies: 4
Views: 505

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)?
by Junghyuk_Park_1I
Thu Jan 26, 2017 7:02 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Degeneracy
Replies: 1
Views: 227

Degeneracy

What exactly is degeneracy conceptually? How is it applied in thermodynamics?
by Junghyuk_Park_1I
Thu Jan 26, 2017 7:00 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Reversible Reaction
Replies: 1
Views: 180

Reversible Reaction

What exactly does it mean when a reaction is reversible? Thank you in advance.
by Junghyuk_Park_1I
Thu Jan 19, 2017 10:22 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Cv vs Cp
Replies: 1
Views: 178

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!
by Junghyuk_Park_1I
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: 273

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!
by Junghyuk_Park_1I
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: 303

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?
by Junghyuk_Park_1I
Fri Dec 02, 2016 2:13 am
Forum: Conjugate Acids & Bases
Topic: Weak Acid/Base-Strong Base/Acid Titration Question
Replies: 1
Views: 286

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...
by Junghyuk_Park_1I
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: 204

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 ...
by Junghyuk_Park_1I
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: 202

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?
by Junghyuk_Park_1I
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: 231

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.
by Junghyuk_Park_1I
Wed Nov 16, 2016 3:22 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Kc vs Kp vs Q [ENDORSED]
Replies: 1
Views: 1689

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.
by Junghyuk_Park_1I
Thu Nov 10, 2016 12:46 am
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: HOMO to LUMO Concept
Replies: 3
Views: 393

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.
by Junghyuk_Park_1I
Wed Nov 02, 2016 9:31 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Bonding vs. Anti-bonding
Replies: 2
Views: 1057

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.
by Junghyuk_Park_1I
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: 497

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.)?
by Junghyuk_Park_1I
Tue Oct 25, 2016 3:24 pm
Forum: Lewis Structures
Topic: Lewis Structure Octet Rule Exceptions
Replies: 4
Views: 472

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...
by Junghyuk_Park_1I
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: 419

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 ...
by Junghyuk_Park_1I
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: 312

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...
by Junghyuk_Park_1I
Fri Oct 14, 2016 3:48 pm
Forum: Trends in The Periodic Table
Topic: Atomic Radius
Replies: 2
Views: 255

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 ...
by Junghyuk_Park_1I
Fri Oct 14, 2016 3:45 pm
Forum: Photoelectric Effect
Topic: Threshold Energy Question
Replies: 1
Views: 227

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...
by Junghyuk_Park_1I
Tue Oct 11, 2016 6:13 pm
Forum: Significant Figures
Topic: Sig fig with constants
Replies: 2
Views: 509

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...
by Junghyuk_Park_1I
Thu Oct 06, 2016 2:38 pm
Forum: Properties of Electrons
Topic: Wavelike Properties? [ENDORSED]
Replies: 2
Views: 416

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,...
by Junghyuk_Park_1I
Thu Oct 06, 2016 2:17 pm
Forum: Student Social/Study Group
Topic: Dykstra Hall Study Group (Fall 2016)
Replies: 25
Views: 1589

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.
by Junghyuk_Park_1I
Thu Sep 29, 2016 4:59 pm
Forum: Photoelectric Effect
Topic: Wave-Particle Duality and Equations Used
Replies: 1
Views: 209

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...
by Junghyuk_Park_1I
Thu Sep 29, 2016 4:47 pm
Forum: Student Social/Study Group
Topic: Dykstra Hall Study Group (Fall 2016)
Replies: 25
Views: 1589

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...
by Junghyuk_Park_1I
Mon Sep 26, 2016 5:03 pm
Forum: Student Social/Study Group
Topic: Dykstra Hall Study Group (Fall 2016)
Replies: 25
Views: 1589

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...
by Junghyuk_Park_1I
Sun Sep 25, 2016 6:03 pm
Forum: Student Social/Study Group
Topic: Dykstra Hall Study Group (Fall 2016)
Replies: 25
Views: 1589

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).

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