Search found 28 matches

by 704647747
Tue Mar 07, 2017 10:52 am
Forum: *Cycloalkanes
Topic: lecture pg 96 methyl ethyl
Replies: 1
Views: 222

lecture pg 96 methyl ethyl

During lecture, professor Lavelle mentioned another way to name isopropyl-cyclopentane (pg. 96): methyl ethyl cyclopentane.

I'm confused as to why it's methyl ethyl instead of ethyl methyl, since I would assume that 'e' comes before 'm' (alphabetically).
by 704647747
Tue Mar 07, 2017 10:44 am
Forum: *Alkanes
Topic: Naming with iso- and neo-
Replies: 8
Views: 860

Re: Naming with iso- and neo-

I'm still having a hard time understanding the difference between neo- and tert- substituents... can someone help explain? thank you!
by 704647747
Wed Mar 01, 2017 12:17 am
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Catalyst
Replies: 6
Views: 605

Re: Catalyst

804748473 wrote:Could someone outline the information we need to know about catalysts because I could not find it in the course reader


page 84 also has a little bit of information on catalysts and free energy (activated complex theory).
by 704647747
Sun Feb 12, 2017 5:56 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Pt(s) when to include in galvanic cell diagram
Replies: 2
Views: 357

Re: Pt(s) when to include in galvanic cell diagram

I read through the chem community answers and understand now-- sorry for a redundant post and thanks.
by 704647747
Sun Feb 12, 2017 5:46 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Pt(s) when to include in galvanic cell diagram
Replies: 2
Views: 357

Pt(s) when to include in galvanic cell diagram

Hi, Do we include Pt(s) as an electrode conductor when both substances are of the same phase (ions or aqueous) (pg 5 crs reader)? I saw another problem in the textbook where Pt(s) is included when one is in its gaseous phase and another in aqueous (q 14.13 c). When exactly do we use Pt(s) as an elec...
by 704647747
Sun Feb 12, 2017 4:18 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Course reader example pg. 7 electrochemistry
Replies: 4
Views: 398

Course reader example pg. 7 electrochemistry

I was reviewing the examples on the course reader, and saw that on page 7, the F constant is listed as =96485C/mol e-. I just wanted to double check that this should be 96,4853 C/mol instead? The answer comes out differently when I substitute F with the value listed on the laminated formula sheet, i...
by 704647747
Tue Jan 31, 2017 10:46 am
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Energy and entropy in equilibrium
Replies: 2
Views: 302

Re: Energy and entropy in equilibrium

OH I think I understand now! Thanks a lot for the analogy. If I understood correctly, in a sense, both the energy and entropy here, are referring to those within a system (where in your example, the system=golf balls)? So when a molecule has high energy, it is able to hold its atoms in place, which ...
by 704647747
Sat Jan 28, 2017 5:10 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Microstates and macroscopic property
Replies: 1
Views: 265

Re: Microstates and macroscopic property

Pg. 30 and a few pages after that serves to explain that delta S (change in entropy) = (q/T) = (-w/T), where w = nRTln(V2-V1). In other words, there is a relationship between entropy (micro state) and volume (bulk property). Likewise, the "example of a link b/w accessible states and macroscopic...
by 704647747
Thu Jan 26, 2017 11:59 am
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Energy and entropy in equilibrium
Replies: 2
Views: 302

Energy and entropy in equilibrium

Hi, During lecture, Dr. Lavelle said that entropy is in its maximum and energy in minimum, in a state of equilibrium. Could someone explain how this works? I thought it would be reasonable to think that energy and entropy is proportional (i.e. more energy input creates more entropy due to greater nu...
by 704647747
Tue Jan 17, 2017 9:52 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: State functions and Path functions, and predictability
Replies: 1
Views: 256

State functions and Path functions, and predictability

Hi,
I was just wondering, if we are able to calculate/predict for a state function by it's final and initial state, is there a way to calculate for other non-state, path functions? Or is it too probabilistic(?)?
by 704647747
Tue Jan 17, 2017 9:45 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Reversible vs. Irreversible Reactions
Replies: 2
Views: 254

Re: Reversible vs. Irreversible Reactions

Practically, I also try to think of the concept in this way: Reversible process: If there is a syringe and you block the open tip of the syringe (so the air is trapped) and try to push in the plunger, then the force will induce a small change, but when you let it go, it'll rise back (be reversed). I...
by 704647747
Sat Jan 14, 2017 10:04 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: heat q(sys)+ q(surr) =0
Replies: 3
Views: 521

Re: heat q(sys)+ q(surr) =0

Thanks for your answer! Definitely helped clarify. Just to double check then, for the example on page 7, the system is the reactants (aqueous HCl and NaOH), and the surrounding is the water? And we calculated the amount of heat released from the system by calculating the amount of heat that the surr...
by 704647747
Sat Jan 14, 2017 9:22 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: heat q(sys)+ q(surr) =0
Replies: 3
Views: 521

heat q(sys)+ q(surr) =0

Hi,
On the course reader (pg. 7), Dr. Lavelle wrote "perfect system" next to heat q(sys)+ q(surr) =0
Does this apply only to closed systems? Is the "perfect system" referring to closed systems?
Thanks.
by 704647747
Thu Feb 18, 2016 11:45 pm
Forum: Second Order Reactions
Topic: difference between consumption and decomposition
Replies: 1
Views: 356

difference between consumption and decomposition

What is the difference between consumption and decomposition of reactions? when do we use consumption instead of decomposition, and does the choice affect the way of calculating the total reaction order?
by 704647747
Thu Feb 18, 2016 11:43 pm
Forum: Second Order Reactions
Topic: ions and reaction orders
Replies: 2
Views: 378

ions and reaction orders

do ions not contribute to reaction orders? If so, why not?
by 704647747
Mon Feb 08, 2016 12:57 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: quiz 1 prep winter 2012 5.
Replies: 3
Views: 390

Re: quiz 1 prep winter 2012 5.

do we need to memorize the value for the midterm? or will only the ones on the worksheet be tested?
by 704647747
Sun Jan 17, 2016 11:15 am
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Internal energy and state property
Replies: 1
Views: 277

Internal energy and state property

Why is P(change in Volume) zero for aqueous solutions, solids and some gases for (change in U) = (change in H) - P(change in V)?
by 704647747
Thu Jan 07, 2016 1:16 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bond enthalpy and Enthalpy change
Replies: 1
Views: 309

Bond enthalpy and Enthalpy change

Enthalpy is the amount of heat released or absorbed at a constant pressure. My question is: What exactly is the conceptual difference between bond enthalpy and enthalpy change? I know that each are different method that can be used to calculate the enthalpy of a reaction, but I'm uncertain as to whe...
by 704647747
Sat Dec 05, 2015 10:59 am
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: 12.49 Stronger Base
Replies: 3
Views: 691

Re: 12.49 Stronger Base

How do we know that BrOH is a weak acid?
by 704647747
Sat Nov 28, 2015 9:28 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Video: Equilibrium concepts and examples
Replies: 2
Views: 343

Video: Equilibrium concepts and examples

Attached is a video covering the basic concepts of Equilibrium with examples that illustrate each concept. Made by Angela He and Jane Park, Chem 14a
by 704647747
Sat Oct 31, 2015 3:42 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: orbitals in sigma-bond overlap
Replies: 1
Views: 146

orbitals in sigma-bond overlap

Why to orbitals in sigma-bond have more overlap than orbitals in pi-bond? Is it because it's located along the bond axis?
by 704647747
Sat Oct 31, 2015 3:38 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Bond order of 1/2 and 0
Replies: 1
Views: 2668

Bond order of 1/2 and 0

What does it mean when the bond order is 1/2 or 0?
Does the bond order of 0 just mean that the molecule is very unstable and will react very easily?
by 704647747
Sun Oct 25, 2015 7:29 pm
Forum: Hybridization
Topic: Ch. 4 #43
Replies: 3
Views: 444

Re: Ch. 4 #43

There are p and s characters. The bond angle increases as s-character increases and decreases as p-character increases. So sp hybridization's bond angle would be higher than that of sp(x) hybridization (since s-character has more 'presence' in sp than in sp(x))
by 704647747
Tue Oct 06, 2015 10:07 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg Equation concept
Replies: 1
Views: 262

Rydberg Equation concept

Why does the equation E=-(h*R)/n^2 have a negative sign to it, when it's derived from E=hR*[(1/ n(final)^2 - 1/n(initial)^2], where neither h nor R are negative?

Is it negative only when the quantum number (n) is going from a higher number to a lower number (i.e. when energy is emitted)?
by 704647747
Tue Oct 06, 2015 9:46 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Negative Frequency with the Rydberg Equation
Replies: 1
Views: 3028

Re: Negative Frequency with the Rydberg Equation

I don't think you should be getting negative frequencies, since the definition of frequency in the context of chemistry (#of waves per second, also measured in Hz) won't make sense if it is negative. I.e., you can't have a negative number of wave per given time. However, the ENERGY TRANSITION can be...
by 704647747
Sat Oct 03, 2015 5:01 pm
Forum: Properties of Light
Topic: Question: Wave Model vs. Photon Model of Light
Replies: 7
Views: 2022

Re: Question: Wave Model vs. Photon Model of Light

Just to recap the experiment, the observations from the experiment showed that 1. no electrons were ejected unless radiation has frequency above a certain threshold value characteristic of the metal 2. electrons were ejected immediately, however low the intensity of the radiation 3. kinetic energy o...

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