## Search found 21 matches

Tue Mar 07, 2017 8:16 pm
Forum: *Alkanes
Replies: 1
Views: 159

Hello! I still do not understand how to label the type of mechanism or reaction when referring to electrophilic addition and others. Is it the number of steps or type of steps? How do I differentiate the different types? Thanks in advance!
Mon Mar 06, 2017 10:43 pm
Forum: Administrative Questions and Class Announcements
Topic: Quiz 3 Winter 2017
Replies: 183
Views: 15496

### Re: Quiz 3 Winter 2017

Cowasjee_Sanaea_3E wrote:For the first question, how do you know it is 4- isopropyldecane? I thought that it was just 4-propyldecane

Can someone please address this? Why do we need the "iso" prefix? Isn't it just a propyl functional group attached to the 4th carbon of a decane compound?
Tue Feb 14, 2017 4:43 pm
Forum: Phase Changes & Related Calculations
Topic: Entalpy related to Temperature
Replies: 2
Views: 338

### Entalpy related to Temperature

How are enthalpy and temperature directly proportional? (How would an increase in one, lead to an increase in the other? Or a decrease?)
Mon Feb 13, 2017 4:04 pm
Forum: Phase Changes & Related Calculations
Topic: When to use different enthalpy values
Replies: 1
Views: 169

### When to use different enthalpy values

I am confused when to use different delta H values. For example, in a problem that says to calculate the heat gained or lost by superheated steam during condensation with constant pressure, why do we use delta H(vap)? Is it because we are dealing with steam? Aren't we talking about condensation and ...
Mon Feb 13, 2017 3:19 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Quiz 1 Question 3 Standard Entropy of Vaporization
Replies: 1
Views: 275

### Quiz 1 Question 3 Standard Entropy of Vaporization

Hello! I am still very lost in the concept of finding standard entropy of vaporization. On my version of the quiz, there was a question regarding this and I am still having trouble understanding how to solve it. The question was as following: For H20, standard delta H(vap, m) = 44.0 kJ/mol at T(vap)...
Sun Feb 12, 2017 6:12 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagrams
Replies: 1
Views: 154

### Re: Cell Diagrams

I'm not sure if it's correct, but when I went to one of the review sessions one of the TA's called it a little mountain (with each side building up to the salt bridge). Meaning compounds without a charge leading to ones with slightly more positive charge to ions with an even more positive charge to ...
Wed Feb 08, 2017 4:46 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Understanding n intuitively
Replies: 1
Views: 160

### Understanding n intuitively

Today in class, professor Lavelle went through how to understand that n would be 1 intuitively in an example from the course reader. In the course reader, it then proceeds how to get the number mathematically. I follow the math but I failed to understand how he knew the value of n before doing the m...
Tue Jan 31, 2017 10:36 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: Exercise 9.37 (Absolute Entropies)
Replies: 2
Views: 244

### Exercise 9.37 (Absolute Entropies)

In the solutions manual, it says to note that the absolute entropies of the elements are not 0, and that the entropy change for the reaction in which a compound is formed from the elements is also not 0. Can someone please explain why both parts are not 0 please? (and when they would be 0)? Please :)
Thu Jan 26, 2017 2:18 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibbs Free Energy Equation Related to S(universe)
Replies: 1
Views: 251

### Gibbs Free Energy Equation Related to S(universe)

Hello there! On page 36 of the course reader, it is discussing why the change in gibbs free energy and how this relates to the spontaneity of a reaction. The course reader says to divide the equation Gsys =Hsys -TSsys by -T to get the equation [-(Gsys)/T] =Ssurr +Ssys. I do not understand how this i...
Mon Jan 23, 2017 9:18 am
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Irreversible and reversible reactions
Replies: 2
Views: 328

### Re: Irreversible and reversible reactions

Can someone explain how the equations for an irreversible and reversible reaction differ conceptually? I understand how with the reversible process reactants can be formed again, but how can this be explained through the equations? What makes each equation reversible or not?
Mon Jan 16, 2017 2:05 pm
Forum: Administrative Questions and Class Announcements
Topic: Tutoring? [ENDORSED]
Replies: 39
Views: 37339

### Re: Tutoring?[ENDORSED]

Did anyone happen to write down how to sign up for AAP Peer Learning and if it is not too late to sign up?
Fri Dec 02, 2016 12:46 pm
Forum: Administrative Questions and Class Announcements
Topic: Final Exam Details and Review Sessions Fall 2016
Replies: 15
Views: 7895

### Re: Final Exam Details and Review Sessions Fall 2016

In the most recent email sent out, it states the final will have no derivations. Can you expand on what this is referring to or what you mean by this?
Tue Nov 15, 2016 5:54 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: General ICE Box Question in Reference to Quiz 3
Replies: 1
Views: 281

### General ICE Box Question in Reference to Quiz 3

When setting up the ICE box for reactions that have molecules with mole ratios that aren't 1:1 (so like 1:2..etc), do you only add 2x when creating a value for the change in molecular concentration, only square the value when at the K step, or square 2x at the K step? If my question seems unclear, I...
Tue Nov 15, 2016 11:46 am
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: pi 2p bonds or sigma 2p bonds [ENDORSED]
Replies: 3
Views: 601

### pi 2p bonds or sigma 2p bonds[ENDORSED]

In discussion we drew the molecular orbital diagram for OF and NF. In the OF diagram, the sigma 2p bond is below the pi 2p bond (and vice versa for the NF diagram). Can someone please explain by these two switch depending on which atoms are bonding? I thought it had something to do with the amount o...
Mon Nov 14, 2016 4:11 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Equilibrium Constant Expressions
Replies: 1
Views: 333

### Equilibrium Constant Expressions

How would you write an equilibrium constant expression a reaction where the reactants/products are in aqueous solutions or are solid?
Sat Nov 05, 2016 11:58 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Bonding vs Antibonding
Replies: 3
Views: 436

### Re: Bonding vs Antibonding

Another way to look at it is to look at bonding in terms of waves, because the particles are moving so quickly it's more of a region of probability. You can think of it in the sense of constructive and destructive interference. Two areas where the electron has a high probability of occurring creates...
Fri Oct 28, 2016 4:26 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Molecular Orbital theory
Replies: 5
Views: 393

### Re: Molecular Orbital theory

I think I remember Dr. Lavelle saying the molecular orbital theory also helps determine the energy differences within a molecule, but I'm not entirely sure.
Fri Oct 21, 2016 12:23 pm
Forum: Lewis Structures
Topic: Lewis Structures
Replies: 6
Views: 433

### Re: Lewis Structures

Regarding Jasmin's question... Page 79 of the course reader instructs us to choose the atom with the lowest ionization energy as the central atom. The nitrogen in ammonium would be the central atom, because of its low ionization energy compared to hydrogen's. (Not to mention hydrogen is never the ce...
Sat Oct 15, 2016 1:07 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 903575

### Re: Post All Chemistry Jokes Here

Reading all these jokes, I think this class is going to be a (pro)ton of fun this year with Mr. Lavelle!
Fri Oct 07, 2016 2:33 pm
Forum: Quantum Numbers and The H-Atom
Topic: Magnetic Quantum Number [ENDORSED]
Replies: 2
Views: 444

### Re: Magnetic Quantum Number[ENDORSED]

Hello! According to my understanding, (and page 63 in the reader), the magnetic quantum number relates back to your angular momentum quantum number, l. The magnetic quantum number can always be the positive and negative value of the angular momentum quantum number, l. Additionally, the numbers count...
Sun Oct 02, 2016 11:47 am
Forum: Student Social/Study Group
Topic: Sproul Hall Chem14A Study Group
Replies: 30
Views: 2277

### Re: Sproul Hall Chem14A Study Group

Hey Everyone! I'm also in Sproul Hall. It doesn't seem like much has been accomplished on planning this study group, but I am very interested in joining. We need times and dates! Personally, I'm usually free on Sundays and during most of the day Tuesdays. If these sound good to other people, I can t...