Search found 14 matches
- Wed Mar 15, 2017 12:44 pm
- Forum: *Cyclohexanes (Chair, Boat, Geometric Isomers)
- Topic: Chair conformation
- Replies: 4
- Views: 888
Re: Chair conformation
To add to the comment above, I know a ring flip changes whatever is axial to equatorial, but is there more to it? What's the significance of this?
- Wed Mar 15, 2017 12:43 pm
- Forum: *Cyclohexanes (Chair, Boat, Geometric Isomers)
- Topic: Chair conformation
- Replies: 4
- Views: 888
Re: Chair conformation
For clarity, what exactly is a ring flip? I have heard the term used multiple times but I'm not exactly sure what it means! Thanks in advance!
- Mon Mar 13, 2017 4:08 pm
- Forum: *ChemDraw
- Topic: steric strain
- Replies: 2
- Views: 1583
Re: steric strain
Strain in general is when a molecule is less stable due to electron repulsion or when it is not in its ideal geometry. Steric strain is the increase in potential energy of a molecule due to repulsion between electrons in atoms.
- Sun Mar 12, 2017 5:49 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Saying Thank You to Dr. Lavelle
- Replies: 490
- Views: 570566
Re: Saying Thank You to Dr. Lavelle
After an abrupt awakening from 14A, I had no idea what to expect coming into this quarter. Now as we enter week 10, I'm ecstatic to say that I not only understand chem more than I ever have before, but I now look forward to 14C rather than dread it. Your countless resources and aids are much appreci...
- Mon Mar 06, 2017 6:13 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Quiz 3 Winter 2017
- Replies: 183
- Views: 29796
Re: Quiz 3 Winter 2017
In response to, "Why is the answer for #4, 4-butyl-1,2-dimethylcyclohexane and not 1,2-dimethyl,4-butylcyclohexane? When naming a compound, do the lower numbers go first?" You list different substituents alphabetically, not based on the numbers. In this example, butyl comes before methyl b...
- Mon Feb 27, 2017 2:34 pm
- Forum: *Alkanes
- Topic: How to Name
- Replies: 3
- Views: 1527
Re: How to Name
How would you name the last example from lecture today:
CH3
|
CH3-CH-CH2-CH2-CH2-CH3
Please explain! I know the methyl group is involved but not sure how! Thank you!
CH3
|
CH3-CH-CH2-CH2-CH2-CH3
Please explain! I know the methyl group is involved but not sure how! Thank you!
- Mon Feb 27, 2017 2:18 pm
- Forum: *Organic Reaction Mechanisms in General
- Topic: Determining Where Hydrogen Bonds
- Replies: 5
- Views: 1107
Re: Determining Where Hydrogen Bonds
Is the explanation above the reason why the curved arrows point from the pi-double bond to the H and why another curved arrow points from the single bond to the Br? I'm not completely sure what the arrows represent. Do the arrows just represent bonds being broken and the transfer of electrons?
- Tue Feb 21, 2017 10:21 am
- Forum: Administrative Questions and Class Announcements
- Topic: Quiz 2 Winter 2017
- Replies: 160
- Views: 24934
Re: Quiz 2 Winter 2017
For #11: I'm not 100% sure this is how to approach this problem, but this is what a friend and I did to solve it! ln k2/k1= Ea/8.314 [1/T1 - 1/T2] k2=35 min^-1 k1=25 min^-1 T1=298 T2=350 Solve for Ea 0.336= 0.000498Ea/8.314 Ea=5617.3 Now find rate constant at 770K ln x/25= 5617.3/8.314 [1/298 - 1/77...
- Fri Feb 17, 2017 4:20 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: Confusion about intermediates
- Replies: 4
- Views: 804
Re: Confusion about intermediates
As stated above, most chemical reactions are stepwise. For clarity, a stepwise reaction is a chemical reaction with one or more reaction intermediates and involves at least two consecutive elementary reactions. An intermediate is formed from the reactants or preceding intermediates and reacts to pro...
- Fri Feb 10, 2017 12:00 pm
- Forum: Balancing Redox Reactions
- Topic: Balancing Redox Reaction with Hydrogens
- Replies: 3
- Views: 609
Re: Balancing Redox Reaction with Hydrogens
My TA gave us a list of steps for how to balance redox reactions! Step 1: Write the skeletons of the half-reactions Step 2: Balance all elements other than H and O Step 3: Balance O by adding H2O to the side without O Step 4: Balance H by adding H+ to the side without H Step 5: Balance charges by ad...
- Thu Feb 02, 2017 2:51 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Battery Cell
- Replies: 1
- Views: 438
Re: Battery Cell
I didn't completely understand the purpose of a salt bridge at first either! Recall that the electrons flow from the anode to the cathode.The anode side (oxidation half-reaction) is producing Zn2+ ions and Cu2+ ions on the cathode side (reduction half-reaction) are being used up. The salt bridge ser...
- Sat Jan 28, 2017 10:14 pm
- Forum: Phase Changes & Related Calculations
- Topic: Quiz 1
- Replies: 11
- Views: 1950
Re: Quiz 1
From what I've heard, quiz 1 is very calculation heavy. Doing the recommended problems in the textbook and the practice quiz in the course reader should definitely help! Make sure to be familiar with all of the equations discussed in class/used in chapter 8, 9, and the 11!
- Sun Jan 22, 2017 7:16 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Boltzmann Equation [ENDORSED]
- Replies: 1
- Views: 451
Re: Boltzmann Equation [ENDORSED]
Entropy (S) is logarithmically related to the degeneracy (W). Using the equation S=Kb ln W makes the "large" error not so significant. Dr. Lavelle used the example of taking the natural log of both 1 million and 1,050,000 million, which seems like a large error but actually have very simil...
- Fri Jan 13, 2017 8:19 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: State Property Difference
- Replies: 2
- Views: 582
Re: State Property Difference
State functions, such as temperature and pressure, have values that do not depend on the path taken to reach that specific value. For state functions, you just need to know the final value and the initial value. Work is not a state function because it is dependent on the path used to go from the ini...