Search found 30 matches

by NinaSheridan
Wed Mar 15, 2017 2:22 am
Forum: Administrative Questions and Class Announcements
Topic: Saying Thank You to Dr. Lavelle
Replies: 209
Views: 97951

Re: Saying Thank You to Dr. Lavelle

Dear Dr. Lavelle, You have actually made me enjoy learning about chemistry and I did not know that was possible! I feel like I have so many resources at my disposal, and using them has made me confident in my own abilities and made me aspire to really understand everything, because I know it's possi...
by NinaSheridan
Wed Mar 15, 2017 2:16 am
Forum: *Cyclohexanes (Chair, Boat, Geometric Isomers)
Topic: Question 3.15
Replies: 2
Views: 346

Re: Question 3.15 plus 3.16 Question

The book says the "largest" is more stable in the equatorial position, so I would say size. However, I'm confused about 3.16 because it doesn't state whether the conformation is more stable when methyl is equatorial or not. I'm assuming it's more stable when it is equatorial, because CH3 i...
by NinaSheridan
Fri Mar 10, 2017 10:13 pm
Forum: *Organic Reaction Mechanisms in General
Topic: Transition Steps
Replies: 7
Views: 785

Re: Transition Steps

Also, for electrophilic addition, we often have a main molecule with a double bond and a molecule with two element s. If a double bond is broken and an atom from the two-element molecule has been added, the other part of the two-part molecule will be added to the other side of the double bond.
by NinaSheridan
Sat Mar 04, 2017 3:53 pm
Forum: *Alkanes
Topic: Naming [ENDORSED]
Replies: 92
Views: 8253

Re: Naming [ENDORSED]

There was also a thing Lavelle mentioned about not using a dash sometimes for the second to last term? It's in our course reader but was different on the powerpoint or something like that.
by NinaSheridan
Fri Feb 24, 2017 1:11 am
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Quiz prep 2 #11
Replies: 4
Views: 526

Re: Quiz prep 2 #11

Because we aren't being tested on it, should we still do the 20 or so problems on it? Is it likely to show up on future tests?
by NinaSheridan
Tue Feb 14, 2017 5:05 pm
Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
Topic: Midterm Winter 2013 problem 5B
Replies: 10
Views: 914

Re: Midterm Winter 2013 problem 5B

If anyone can explain why we look at molar mass rather than the possible positions of the molecule that would be great :)
by NinaSheridan
Tue Feb 14, 2017 12:24 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Nernst Equation [ENDORSED]
Replies: 4
Views: 486

Re: Nernst Equation [ENDORSED]

But (298)(8.314)/(964853) = .025678, not .05916, so where is .05916 coming from? A different form of the gas constant? A different temperature??
by NinaSheridan
Thu Feb 09, 2017 3:10 am
Forum: Balancing Redox Reactions
Topic: General Guidelines for Writing Half Reactions
Replies: 1
Views: 248

Re: General Guidelines for Writing Half Reactions

As I understand it, you split up the equation into the oxidation reaction and the reduction reaction. First, put them in their reduction form because E(standard) values are given for reduction reactions. Then, depending on which reaction is actually an oxidation reaction in the equation (you can fin...
by NinaSheridan
Fri Feb 03, 2017 5:28 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Quiz 1 prep #9
Replies: 2
Views: 275

Re: Quiz 1 prep #9

If you're still confused about why entropy of the system and entropy of the surroundings aren't both zero (why option A and B aren't correct if entropy in general is a state function), the situation with isothermal reversible reactions having a net change of zero while irreversible reactions have an...
by NinaSheridan
Tue Jan 24, 2017 11:18 am
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Homework Problem 8.51
Replies: 2
Views: 308

Homework Problem 8.51

For question 51 in chapter 8, the problem tells us the enthalpy of formation for TNT (-67kJ/mol) and the density (1.65g/cm^3). It then gives us the equation 4 C7H5N3O6 + 21 O2 --> 28 CO2 + 10 H20 + 6N2. It asks to find its enthalpy density. I understand how to find the enthalpy of the equation, but ...
by NinaSheridan
Tue Jan 24, 2017 11:02 am
Forum: Phase Changes & Related Calculations
Topic: Homework Help 8.9
Replies: 4
Views: 396

Re: Homework Help 8.9

When would we use one constant over the other? Does it have to do with units?
by NinaSheridan
Fri Jan 20, 2017 12:30 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Homework 8.25
Replies: 5
Views: 2397

Re: Homework 8.25

Also why do we completely ignore the masses that are given? Isn't the equation (m)(c)(deltaT)? Why do we disregard the masses and the moles?
by NinaSheridan
Thu Jan 19, 2017 11:28 am
Forum: Phase Changes & Related Calculations
Topic: Different enthalpy of vaporizations for water
Replies: 3
Views: 267

Re: Different enthalpy of vaporizations for water

I'm a little confused about the idea of "standard states" to begin with. For example, a gas is only in its standard state at 1 atm. So what if it isn't at 1 atm? What does that make it? Does that just mean the reaction enthalpy isn't the standard reaction enthalpy?
by NinaSheridan
Thu Jan 12, 2017 12:29 am
Forum: Phase Changes & Related Calculations
Topic: Sublimiation
Replies: 6
Views: 591

Re: Sublimiation

I looked this up too and also found that in the case of liquids going to solids (the opposite of fusion) it's technically called solidification or crystallization if that ever comes up anywhere :)
by NinaSheridan
Sat Dec 03, 2016 11:41 pm
Forum: Student Social/Study Group
Topic: Most efficient way to study w/ only 3 days until the midterm
Replies: 5
Views: 3141

Re: Most efficient way to study w/ only 3 days until the midterm

I've been told the test might be more conceptual (more like the practice final from 2015 than the ones from earlier years) so it might be helpful to look at the practice test from 2015, and the conceptual problems and the concepts at the beginning of each chapter. Knowing calculations wouldn't be a ...
by NinaSheridan
Tue Nov 29, 2016 5:56 pm
Forum: Calculating the pH of Salt Solutions
Topic: Homework 12.65
Replies: 5
Views: 852

Re: Homework 12.65

If that's the case though, why isn't KF neutral as well?
by NinaSheridan
Sat Nov 26, 2016 2:29 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Homework Problem #57
Replies: 1
Views: 228

Re: Homework Problem #57

Jk, just answered my own question, but if anyone else has this problem, here's what's going on. The answer key is using a different method that uses the reaction stoichiometry rather than the concentrations, but the concentration method works too, so it's just a different method.
by NinaSheridan
Sat Nov 26, 2016 2:20 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Homework Problem #57
Replies: 1
Views: 228

Homework Problem #57

So on 11.57 the answer key says the initial concentration for H2 is 3 moles per liter, but the problem itself says it's 3 moles for 10 L, which would make the concentration .3 instead of 3, wouldn't it? It does the same thing for CO, it says 2 moles are put into a 10L vessel, which would make the co...
by NinaSheridan
Fri Nov 25, 2016 8:47 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Strong Acid or Weak Acid
Replies: 3
Views: 547

Re: Strong Acid or Weak Acid

As to the above comment ^^, you mean electronegativity of a specific element like the central element? Or all the average of the elements overall?
by NinaSheridan
Mon Nov 14, 2016 7:28 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Homework 17.33
Replies: 2
Views: 340

Re: Homework 17.33

This is related, if someone can explain this, can they also explain why oxalato is only bidentate?
by NinaSheridan
Mon Nov 14, 2016 5:23 am
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Homework problem 4.61
Replies: 1
Views: 279

Homework problem 4.61

What do the (sigma2p)^22 and (sigma2p)^11 mean at the end of #61 on the chapter 4 homework?
by NinaSheridan
Wed Nov 09, 2016 6:43 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: NH2 Bonds
Replies: 2
Views: 595

NH2 Bonds

When we used NH2 in class, several times we referred to it as having on electron pair, but shouldn't NH2 have two pairs of unbound valence electrons?
by NinaSheridan
Thu Nov 03, 2016 6:14 pm
Forum: Hybridization
Topic: Dipole Moment
Replies: 2
Views: 371

Re: Dipole Moment

It depends on electronegativity, not formal charge :)
by NinaSheridan
Fri Oct 28, 2016 3:45 pm
Forum: Ionic & Covalent Bonds
Topic: Ionic and Covalent Character
Replies: 5
Views: 8869

Re: Ionic and Covalent Character

So based on this logic, any bond with small ionic character (such as elements of the same group, or the same element bonding with another atom of the same element) would have the highest covalent character, and elements far apart from one another on the periodic table would have low covalent charact...
by NinaSheridan
Thu Oct 20, 2016 2:12 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Textbook Question 2.37 part b [ENDORSED]
Replies: 3
Views: 451

Re: Textbook Question 2.37 part b [ENDORSED]

Wait I just answered my own question, but in case other people are also confused by this, maybe it will help. Effective nuclear charge has to do with the pull from the nucleus on electrons in their respective orbitals, so an electron in an s orbital will have a stronger attraction to the nucleus tha...
by NinaSheridan
Thu Oct 20, 2016 2:03 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Textbook Question 2.37 part b [ENDORSED]
Replies: 3
Views: 451

Re: Textbook Question 2.37 part b [ENDORSED]

I also have a question on 2.37 but it's for part d. So an electron in an s orbital has a lower energy than an electron in a p orbital, but it has a higher effective nuclear charge. What exactly is effective nuclear charge and does it have an inverse relationship to the energy of the electron?
by NinaSheridan
Fri Oct 14, 2016 3:05 pm
Forum: Properties of Light
Topic: QUIZ 1 [ENDORSED]
Replies: 7
Views: 895

Re: QUIZ 1 [ENDORSED]

For later quizzes, should we have specific polyatomic ions memorized?
by NinaSheridan
Tue Oct 04, 2016 5:13 pm
Forum: Ionic & Covalent Bonds
Topic: Copper (I) Oxide [ENDORSED]
Replies: 1
Views: 206

Copper (I) Oxide [ENDORSED]

Does the roman numeral between copper and oxide mean the oxygen atom is negatively charged or the copper atom?
by NinaSheridan
Mon Sep 26, 2016 2:08 pm
Forum: Student Social/Study Group
Topic: Dykstra Hall Study Group (Fall 2016)
Replies: 25
Views: 1752

Re: Dykstra Hall Study Group (Fall 2016)

Hey guys! I'm Nina, and I'd love to join too. Maybe we could all just exchange numbers when we have a few more people; we could meet once a week/before tests for anyone who wants to and that way we can text each other for small things/if we can't make it to a scheduled time?

Go to advanced search