Search found 17 matches
Re: Z and E
Thank you for pointing out my error. I fixed my explanation so hopefully it will better help students understand.
Re: Z and E
And here's a version of E 1-bromo-2chlorethene. 4575447.png Notice how the Bromine and Chlorine are on opposite sides of the double bond? i.e.:Chlorine is above the carbons and Bromine is below. This would be a version of "E" or a molecule where the heaviest molecules are on different side...
Re: Z and E
Hi Leornardo! So I think it's important to distinguish that there is a slight difference between cis and trans and a Z and E molecule. Yes, both are used to establish whether molecules are on the same or opposite side, but we use cis/trans in our class to distinguish hydrocarbon chains and we use Z ...
- Sat Mar 11, 2017 12:54 pm
- Forum: *Alkanes and Substituted Alkanes (Staggered, Eclipsed, Gauche, Anti, Newman Projections)
- Topic: Torsional Strain [ENDORSED]
- Replies: 5
- Views: 1414
Re: Torsional Strain [ENDORSED]
Hi! So torsional strain happens when a molecule in a the stable staggered form becomes eclipsed because of collisions. When a molecule becomes eclipsed, the hydrogens end up becoming closer to each other. (see the two diagrams of ethane. Notice how the two hydrogens are closer together on the eclips...
- Sat Mar 11, 2017 12:22 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Saying Thank You to Dr. Lavelle
- Replies: 490
- Views: 504203
Re: Saying Thank You to Dr. Lavelle
So I guess I'll go first: Dr. Lavelle, Thank you so much for making chemistry super interesting this quarter. I'd previously learned about thermodynamics and rate mechanisms in high school, but it wasn't until this class that I began to really understand and enjoy the material. I'm grateful for all ...
- Sat Mar 11, 2017 12:20 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Saying Thank You to Dr. Lavelle
- Replies: 490
- Views: 504203
Saying Thank You to Dr. Lavelle
Hi Everyone,
Since the quarter is almost over and we have just a week of classes left, I thought it might be nice to start a forum on chemistry community where we could express our appreciation for everything Dr. Lavelle has done for us to help us succeed in Chemistry 14B.
Since the quarter is almost over and we have just a week of classes left, I thought it might be nice to start a forum on chemistry community where we could express our appreciation for everything Dr. Lavelle has done for us to help us succeed in Chemistry 14B.
- Tue Mar 07, 2017 3:18 pm
- Forum: *Cycloalkanes
- Topic: Extra Nomenclature Practice
- Replies: 3
- Views: 977
Re: Extra Nomenclature Practice
Does anyone know how to view the answers to these problems?
- Tue Mar 07, 2017 10:47 am
- Forum: *Cycloalkanes
- Topic: Extra Nomenclature Practice
- Replies: 3
- Views: 977
Re: Extra Nomenclature Practice
Thanks Daniel! This is actually super helpful.
- Thu Feb 23, 2017 9:04 pm
- Forum: *Organic Reaction Mechanisms in General
- Topic: Approaching Organic Chemistry Problems in the Textbook [ENDORSED]
- Replies: 1
- Views: 422
Approaching Organic Chemistry Problems in the Textbook [ENDORSED]
As a first time learner of Organic Chemistry, I had some difficulty attempting to solve problems 1-10 in chapter four. Often times, the problems expect you to know organic chemistry terminology we haven't really discussed in class. For example, Question 4.1 A parts B and C ask us to give the hybridi...
- Wed Feb 22, 2017 7:33 am
- Forum: *Enzyme Kinetics
- Topic: Quiz #9
- Replies: 2
- Views: 711
Re: Quiz #9
Hi Melissa, So for #9 they give you four options and we need to find the incorrect one. Let's go through them together. a) When the concentration of the substrate is low, the rate of an enzyme-catalyzed reaction increases with the concentration of the substrate. This one is true because essentially ...
- Mon Feb 20, 2017 7:52 pm
- Forum: Zero Order Reactions
- Topic: Zero Order Classification [ENDORSED]
- Replies: 2
- Views: 831
Re: Zero Order Classification [ENDORSED]
Hi Jake, So I think another way to understand what a zero order reaction means is to consider that you may have a reaction where the rate of the reaction doesn't depend on how much reactant you have. In other words, it could depend on another variable like enzymes or catalysts. For example, in our b...
- Mon Feb 13, 2017 8:34 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Winter 2014 Midterm Q3C
- Replies: 1
- Views: 437
Re: Winter 2014 Midterm Q3C
Hi Amy, To answer your question, I think they decided to substitute the delta n value with (77.0408g/18.02g) because that is the change in moles of steam. Essentially what is happening is that as the water gets heated and converts to steam, the steam does work on its surroundings. We know that the w...
- Mon Feb 13, 2017 8:23 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Winter 2014 Midterm: Question 5C
- Replies: 1
- Views: 460
Winter 2014 Midterm: Question 5C
Question 5C asks you to classify whether G, S, H, s, q, and E are state functions or not. One thing I was curious about was why E (electric potential) is not a state function. Would someone mind telling me why?
- Sun Feb 05, 2017 10:32 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidation [ENDORSED]
- Replies: 4
- Views: 1396
Re: Oxidation [ENDORSED]
Hi Amy! To answer your question, there is a difference between oxidation and reduction as well as oxidizing agents and reducing agents. Oxidation is where a substance loses electrons. For example, in the reaction : H 2 (g) + F 2 (g) --> 2HF(g) Hydrogen is oxidized because it goes from being H 2 to 2...
- Sun Jan 29, 2017 12:16 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Heat
- Replies: 1
- Views: 556
Re: Heat
Hi Novelpreet, I think the best way to figure out how to use the equations you're confused about is to understand what each equation means. The first equation q=C*delta T essentially tells us that we don't need know how much substance is in the reaction (i.e.: we don't need to know the mass or the #...
- Fri Jan 20, 2017 11:37 pm
- Forum: Calculating Work of Expansion
- Topic: Lecture question [ENDORSED]
- Replies: 2
- Views: 706
Re: Lecture question [ENDORSED]
Hi! So essentially you have a container of an ideal gas with a volume V and a vacuum. (For the most part, you can just ignore the vacuum because its just part of the setup and only thing that happens to the vacuum is that it becomes smaller as the ideal gas expands.) This volume is being held by a e...
- Mon Jan 09, 2017 7:54 pm
- Forum: Phase Changes & Related Calculations
- Topic: Understanding why enthalpy is a state function
- Replies: 4
- Views: 6402
Understanding why enthalpy is a state function
In lecture today, we defined enthalpy as the amount of heat absorbed/released in a system where pressure of constant. Given this definition, I'm still having trouble understanding conceptually why enthalpy is a state function. Could someone clarify this for me?