Search found 23 matches

by HoganFenster2E
Sat Mar 05, 2016 8:22 pm
Forum: *Alkanes and Substituted Alkanes (Staggered, Eclipsed, Gauche, Anti, Newman Projections)
Topic: Anti Conformation
Replies: 2
Views: 482

Anti Conformation

For this molecule, I know it is staggered but would it also be considered in its anti-conformation since the two largest atoms are opposite of each other?
by HoganFenster2E
Thu Mar 03, 2016 6:01 pm
Forum: *Alcohols
Topic: Naming priority between double bond and functional group
Replies: 4
Views: 9607

Re: Naming priority between double bond and functional group

I am not sure if that is true because in this example from Kahn Academy the double bond got the priority for the lower number.
by HoganFenster2E
Sun Feb 28, 2016 1:32 pm
Forum: *Free Energy of Activation vs Activation Energy
Topic: Question 4.37 in O-Chem Book
Replies: 1
Views: 302

Question 4.37 in O-Chem Book

When commenting on the possible values for standard enthalpies of activation (delta H) and standard entropies of activation (delta S) why are delta H values always unfavorable positive and why are delta S values often unfavorable negative? The book answer key gives a little explanation but I don't r...
by HoganFenster2E
Sat Feb 27, 2016 4:02 pm
Forum: *Alkenes
Topic: Differences in Naming Compounds
Replies: 1
Views: 392

Differences in Naming Compounds

Is (3Z, 5E)-3-bromoocta-3,5-diene the same as:
(3Z, 5E)-3-bromo-3,5-octadiene?

In other words, is it ok to say 3,5-octadiene instead of putting the 3,5 between octa and diene?
by HoganFenster2E
Fri Feb 26, 2016 2:51 pm
Forum: *Alkanes
Topic: Cis- versus Trans-
Replies: 1
Views: 315

Cis- versus Trans-

When do we indicate when an organic compound is Cis or Trans? In all of the solutions for chapter one it is never really indicated.
by HoganFenster2E
Fri Feb 26, 2016 2:04 pm
Forum: *Alkanes
Topic: Cis- versus Trans-
Replies: 2
Views: 395

Cis- versus Trans-

When do we indicate when an organic compound is Cis or Trans? In all of the solutions for chapter one it is never really indicated.
by HoganFenster2E
Tue Feb 16, 2016 2:40 pm
Forum: Second Order Reactions
Topic: 2016 Winter Workbook pg. 36 #10
Replies: 1
Views: 375

2016 Winter Workbook pg. 36 #10

For the problem:
Consider the reaction A+B-->C+D rate=k[A]squared
The time it takes for [A] to decrease from 1.0 to 0.50M is the same as the time it takes [A] to decrease from 0.50 to 0.25M. True or false?

Why is this false?
by HoganFenster2E
Tue Feb 02, 2016 5:40 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Adding an Electrode to a Cell Diagram?
Replies: 1
Views: 425

Adding an Electrode to a Cell Diagram?

For the Cell Diagram in the attached photo, why is Platinum only added to the Cathode and not the Anode? The original reaction was 2NO3- (aq) + 8H+ (aq) +6Hg(l) > 3Hg2 2+ (aq) + 2NO (g) + 4H2O (l)
Also when do we add an electrode like platinum to a cell diagram?
by HoganFenster2E
Sun Jan 31, 2016 8:00 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Moles for Free Energy
Replies: 1
Views: 320

Moles for Free Energy

For the questions that have us find the standard reaction Gibbs free energy and give us a reaction, how do we know how many moles to use? Basically, where do we find the amount of moles to use?
by HoganFenster2E
Sun Jan 24, 2016 1:02 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Homework 9.13
Replies: 1
Views: 447

Homework 9.13

When we are calculating change in entropy with a change in volume and temperature of a gas, why do we assume that there is just 1 mole of gas? In the problem we are give the two different volumes and the two different temperatures. We also assume ideal behavior of the gas.
by HoganFenster2E
Mon Jan 18, 2016 1:07 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Heat Transfer Equations
Replies: 2
Views: 489

Heat Transfer Equations

When do we use Q=C x Delta T versus Q=n x C x Delta T? For example in question 8.53 we needed to find the heat released from burning 1.40 grams of CO in a bomb calorimeter and the equation q=C x Delta T was used. Why was this equation used and why do we sometimes include the moles/grams (n) in the e...
by HoganFenster2E
Mon Jan 18, 2016 12:06 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Delta H and what it represents
Replies: 1
Views: 443

Delta H and what it represents

When do we know Delta H is pr mole. I though that Delta H was just the energy in Joules, however in homework problem 8.45 the Delta H is per mole according to the solutions manual. Also, how do we know what Delta H is representing in different problems?
by HoganFenster2E
Sun Jan 10, 2016 9:31 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Homework Order
Replies: 1
Views: 256

Homework Order

For chapter 8, I know we are going somewhat backwards as compared to the book, but what is the order of homework we should do in accordance to the lectures?
by HoganFenster2E
Fri Dec 04, 2015 12:38 am
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8201
Views: 1432285

Re: Chemistry Jokes

My TA threw some Sodium Chloride at me in discussion today...

That's a-salt!
by HoganFenster2E
Tue Dec 01, 2015 6:45 pm
Forum: Lewis Structures
Topic: N2O4 Lewis Structure
Replies: 1
Views: 1900

N2O4 Lewis Structure

In the attached photo, why is the boxed Lewis Structure incorrect and the one below it correct for the best structure. All of the formal charges are zero in the boxed one. This came from the first final exam in the course reader.
by HoganFenster2E
Tue Nov 24, 2015 3:38 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 12.67 Calculating pH from Molarity and Formula
Replies: 1
Views: 520

12.67 Calculating pH from Molarity and Formula

For question 12.67 in the homework, when you are given the molarity and molecular formula, how are we supposed to go about ranking the pH. I was thinking the ice box however the solutions manual does not do this. It seems like it does it a much easier way. Can you rank the pH's just by looking at th...
by HoganFenster2E
Mon Nov 16, 2015 10:45 am
Forum: Naming
Topic: Simply way of how to name complex coordination compounds
Replies: 1
Views: 305

Re: Simply way of how to name complex coordination compounds

For the rules on naming, the book has a chart on page 741. However, when I first looked at it it was a little confusing. I found this video and it helped a lot after reading the book chart. It is a bunch of examples and doing them as the video did them helped. https://www.youtube.com/watch?v=RKXYxTO...
by HoganFenster2E
Thu Nov 05, 2015 5:47 pm
Forum: Naming
Topic: Aqua versus Hydro in Coordination Compounds
Replies: 1
Views: 354

Aqua versus Hydro in Coordination Compounds

In the course reader, it says that H2O's name is aqua, however it also is hydro sometimes. What is the difference between the two and when do I use each?
by HoganFenster2E
Sat Oct 31, 2015 12:04 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Bond Order and # of Electrons for stability
Replies: 3
Views: 700

Bond Order and # of Electrons for stability

I know that the higher the bond order the more stable the molecule, but how does number of electrons (perhaps bonded or unbounded) play into how stable a molecule is? The question I am referring to gives both the bond order and number of electrons for a compound and asks for increasing stability, bu...
by HoganFenster2E
Sun Oct 25, 2015 1:22 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Determining Resonance
Replies: 3
Views: 628

Re: Determining Resonance

I think that you usually need to calculate the formal charges. It is a good way to check your work too, especially if the compound has a negative or positive charge, because it must have that charge. Also, a little shortcut is (I'm not sure how helpful this is) that whenever you have an Oxygen with ...
by HoganFenster2E
Thu Oct 15, 2015 10:13 pm
Forum: Resonance Structures
Topic: What is or isn't a Resonance Structure?
Replies: 2
Views: 545

What is or isn't a Resonance Structure?

According to the solutions manual chapter three question 45, the boxed lewis structure in the attached image is not a resonance structure. Why not? it has 24 electrons and octets for all the atoms involved.
by HoganFenster2E
Sat Oct 10, 2015 2:34 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Beginning the F orbital for electron configurations
Replies: 2
Views: 384

Beginning the F orbital for electron configurations

The course reader does not seem to go into detail for the F-orbital so do we need to know the configurations of atoms lower in the D block with F-orbitals? There seems to be more exceptions (similar to Chromium and Copper maybe) as you move further down in the periodic table. If so, when does the f-...
by HoganFenster2E
Sat Oct 10, 2015 2:17 pm
Forum: Trends in The Periodic Table
Topic: Electron affinity trends
Replies: 2
Views: 651

Re: Electron affinity trends

It is not as periodic as atomic radius or ionization energy, but generally electron affinity is higher for the elements in the top right of the periodic table. However there are a few exceptions like how Carbon's electron affinity is higher than nitrogen's.

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