Search found 23 matches

by Nerissa_Low_2F
Thu Mar 16, 2017 5:49 pm
Forum: Administrative Questions and Class Announcements
Topic: Saying Thank You to Dr. Lavelle
Replies: 337
Views: 140036

Re: Saying Thank You to Dr. Lavelle

Dr. Lavelle, Thank you for the past 2 quarters of chemistry. Your lectures always conveyed your enthusiasm for chemistry and for the wellbeing and education of your students and I greatly appreciated it, as well as the extensive amount of time you put into chemistry community, organizing UA sessions...
by Nerissa_Low_2F
Sun Mar 12, 2017 1:40 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: ch15 #51
Replies: 3
Views: 463

Re: ch15 #51

I think the rate law is only governed by the slow step, so the overall rate law would be that of the first step.
by Nerissa_Low_2F
Tue Feb 28, 2017 2:20 pm
Forum: *Alkanes
Topic: Naming [ENDORSED]
Replies: 92
Views: 10523

Re: Naming [ENDORSED]

I think dashes are typically used to separate numbers from words but I'm not completely sure.
by Nerissa_Low_2F
Wed Feb 22, 2017 5:21 pm
Forum: *Organic Reaction Mechanisms in General
Topic: Activation Energy vs Free energy of activation
Replies: 3
Views: 595

Re: Activation Energy vs Free energy of activation

The activation energy is the energy required by a reaction to actually proceed to completion. Free energy of activation refers to Gibbs free energy. When something is referencing E>Ea, it's talking about whether or not the specific reaction or collision etc. has more energy than the activation energ...
by Nerissa_Low_2F
Wed Feb 22, 2017 5:17 pm
Forum: Administrative Questions and Class Announcements
Topic: Quiz 2 Prep answers
Replies: 2
Views: 505

Re: Quiz 2 Prep answers

They've already been posted in another thread.
by Nerissa_Low_2F
Sat Feb 18, 2017 6:48 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Quiz prep 2 #11
Replies: 4
Views: 680

Re: Quiz prep 2 #11

I'm not sure how to find the rate constant here, but I believe the units for activation energy is kJ/mol. Also, I think we aren't being tested on the Arrhenius equation for the quiz.
by Nerissa_Low_2F
Mon Feb 13, 2017 8:10 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Increase in entropy
Replies: 2
Views: 360

Re: Increase in entropy

If a gas is allowed to occupy a larger volume, there are more states it can possibly be in (because of the larger volume of space) therefore entropy increases. Similarly, if the temp of a gas increases, then the equation for deltaS = nC ln (T2/T1) is positive, indicating an increase in entropy.
by Nerissa_Low_2F
Sat Feb 04, 2017 2:00 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Units of entropy [ENDORSED]
Replies: 3
Views: 536

Re: Units of entropy [ENDORSED]

Yes it is possible. Entropy can be equal to q/T, and the units for q is Joules and Kelvin for T, so the units of your answer can be Joules/Kelvin.
by Nerissa_Low_2F
Fri Jan 27, 2017 4:01 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Clarification on heat transfer but no temp change
Replies: 2
Views: 335

Re: Clarification on heat transfer but no temp change

The only time I can really think of this is happening is during a phase change. During this time, you can think of there being no temperature change because the heat is being fully used to break bonds to go from solid to liquid or liquid to gas.
by Nerissa_Low_2F
Fri Jan 27, 2017 3:55 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Spontaneous
Replies: 1
Views: 303

Re: Spontaneous

I believe it is because you're going from a higher energy to a lower energy, which is more favorable than the opposite direction.
by Nerissa_Low_2F
Thu Jan 12, 2017 6:37 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Units of Reaction Enthalpies
Replies: 11
Views: 1624

Re: Units of Reaction Enthalpies

I think reaction enthalpies are usually written in kJ/mol.
by Nerissa_Low_2F
Fri Dec 02, 2016 5:31 pm
Forum: *Titrations & Titration Calculations
Topic: Half way stoichiometric point
Replies: 1
Views: 326

Re: Half way stoichiometric point

I assume this means at the buffer point? If you use the Henderson Hasselbach equation, you see that pH = pKA + (log[base]initial/log[acid]initial). At the buffer point, the [base]initial = [acid]initial, and the log of 1 =0. Therefore, at this point, pH=pKA
by Nerissa_Low_2F
Fri Nov 25, 2016 2:12 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8731
Views: 1489366

Re: Post All Chemistry Jokes Here

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by Nerissa_Low_2F
Fri Nov 18, 2016 1:35 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Bronsted Acids Clarification
Replies: 1
Views: 377

Re: Bronsted Acids Clarification

I think it's because they don't disassociate completely in water, so there are still a substantial number of disassociated molecules with the carboxyl group in the solution.
by Nerissa_Low_2F
Thu Nov 10, 2016 12:13 pm
Forum: Naming
Topic: 17.31 d
Replies: 1
Views: 316

Re: 17.31 d

I think ligands are written alphabetically in the name of the compound but not necessarily in the formula.
by Nerissa_Low_2F
Sun Nov 06, 2016 5:40 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Fall 2014 Quiz 2 prep #9
Replies: 1
Views: 408

Re: Fall 2014 Quiz 2 prep #9

Atoms that are paramagnetic have unpaired electrons, and atoms that are diamagnetic have no unpaired electrons. I think it would be possible to have an atom with an even number of electrons be paramagnetic when you have an atom with 4 electrons in the p orbital; 2 electrons would be unpaired, making...
by Nerissa_Low_2F
Thu Oct 27, 2016 12:51 pm
Forum: Octet Exceptions
Topic: Free Radicals
Replies: 2
Views: 628

Re: Free Radicals

I think you would know when to draw a free radical by counting the number of electrons. Since radicals have 1 unpaired electron, they will always have an odd number of electrons as opposed to the even number of electrons that other compounds would have. As for which atom the unpaired electron would ...
by Nerissa_Low_2F
Thu Oct 20, 2016 9:58 am
Forum: Lewis Structures
Topic: Octet Rule Exceptions? [ENDORSED]
Replies: 3
Views: 609

Re: Octet Rule Exceptions? [ENDORSED]

Yes, Phosphorus and Sulfur are exceptions because they are in the 3p area of the periodic table. If we look at quantum numbers, Phosphorus and Sulfur both have n=3. Therefore they can both have l for up to 2. l represents the possible orbitals that an element can possess, and if it is possible for l...
by Nerissa_Low_2F
Thu Oct 20, 2016 9:51 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: General Rules on Writing e- Configurations [ENDORSED]
Replies: 2
Views: 546

Re: General Rules on Writing e- Configurations [ENDORSED]

So, when we write electron configurations, we fill in electrons for elements based on their order in the periodic table. This is the only "general rule" to follow. When the d orbital becomes available, you would still fill the 4s first, and then proceed filling those in the d orbital. The ...
by Nerissa_Low_2F
Sat Oct 15, 2016 12:05 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: S, P, D, and F Orbitals [ENDORSED]
Replies: 4
Views: 762

Re: S, P, D, and F Orbitals [ENDORSED]

Basically, these orbitals are the wavefunctions of electrons within an atom, so they are mathematical expressions. When we take the square of the wavefunction, we obtain the probability of finding an electron within an area. The reason they are pictured as "spaces" is because people typica...
by Nerissa_Low_2F
Sat Oct 15, 2016 11:53 am
Forum: Administrative Questions and Class Announcements
Topic: Quiz Grades
Replies: 3
Views: 660

Re: Quiz Grades

Maybe we'll get the quizzes back in our discussion section next week? I'm not completely sure, but I do know that even though the quizzes and tests are assigned a numerical score, the final grade is based on a curve.
by Nerissa_Low_2F
Fri Oct 07, 2016 10:25 am
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Why h/4π?
Replies: 2
Views: 798

Re: Why h/4π?

I'm pretty sure the value was derived experimentally. My TA said that there was a lot of quantum mechanics behind the final derivation of the value that we don't need to know for this class.
by Nerissa_Low_2F
Sat Oct 01, 2016 12:28 pm
Forum: Molarity, Solutions, Dilutions
Topic: Clarification for G.7
Replies: 2
Views: 467

Re: Clarification for G.7

I believe the question is saying that there is 510 g of the aqueous solution total, and then asking you to figure out the masses of each part of the solution.

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