If a question asks us to identify a mechanism (2013 5C), would nucleophilic substitution be as valid an answer as SN2 (given as answer)?
Is there SN1?
Search found 35 matches
- Thu Mar 16, 2017 10:11 pm
- Forum: *Nucleophilic Substitution
- Topic: SN2 vs "Nucleophilic sub"
- Replies: 2
- Views: 840
- Wed Mar 15, 2017 1:10 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Final 2013 Question 4
- Replies: 2
- Views: 539
Re: Final 2013 Question 4
Generally, you should use the log equation when also looking for pH. Otherwise, I think it is easier to use the natural log.
- Sun Mar 12, 2017 2:15 pm
- Forum: Student Social/Study Group
- Topic: Chemistry News
- Replies: 80
- Views: 50753
Re: Chemistry News
Tina that is so interesting! Thank you so much for sharing. I really enjoy Dr. Olah's work! Great read!
- Sat Mar 04, 2017 9:58 pm
- Forum: *Nucleophiles
- Topic: H2O [ENDORSED]
- Replies: 4
- Views: 707
Re: H2O [ENDORSED]
The lone pairs on oxygen!
- Tue Feb 28, 2017 12:10 am
- Forum: *Organic Reaction Mechanisms in General
- Topic: Graph of first and zero order reactions
- Replies: 2
- Views: 691
Re: Graph of first and zero order reactions
The rate law should be the indication.
- Fri Feb 24, 2017 12:57 am
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Intermediates in pre equilibrium
- Replies: 9
- Views: 2311
Intermediates in pre equilibrium
When you replace the intermediate in the rate law when doing pre equ problems, what do you do if you end up with another intermediate in your answer? ClO-+H2O<->HClO+OH- fast HClO+I-<->HIO+Cl- slow HIO+OH-<->IO-+H2O fast so the rate would be k2[HClO][I-] but HClO is an intermediate; K=[OH-][HClO]/[C...
- Wed Feb 22, 2017 1:51 am
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Questions about K on pg 73 of CR
- Replies: 1
- Views: 345
Questions about K on pg 73 of CR
On page 73 of the CR, K was set equal to k1/k'1, why do we assume it is for the NO+NO<->N2O2 reaction? Why is K not equal to [NO2]^2/[N2O2][O2] reaction, k2/k'2? How do we determine this? Please elaborate this step. Also--is "k=2k2*K" going to be given? It seems we just set it equal at the...
- Tue Feb 14, 2017 12:08 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Midterm 2014 Question 6
- Replies: 1
- Views: 400
Midterm 2014 Question 6
K=e^13.2 is what the CR does, but when I do it, I use the full number e^13.20417583... which varies my answer from the given, 540365, to 542626.
This is a fairly large difference and the final answer is worth 4 pts. Would we get points for doing it either way? CR or round at end way.
This is a fairly large difference and the final answer is worth 4 pts. Would we get points for doing it either way? CR or round at end way.
- Fri Feb 10, 2017 2:27 am
- Forum: First Order Reactions
- Topic: First vs. Second Order
- Replies: 7
- Views: 1201
Re: First vs. Second Order
How many orders can you have? Does it keep going?
- Wed Feb 01, 2017 11:17 pm
- Forum: Balancing Redox Reactions
- Topic: Pneumonic Device
- Replies: 3
- Views: 605
Re: Pneumonic Device
also LEO GER
Lose electrons oxidized
Gain electrons reduced
Lose electrons oxidized
Gain electrons reduced
- Sun Jan 29, 2017 1:25 am
- Forum: Administrative Questions and Class Announcements
- Topic: Quiz Preparation
- Replies: 3
- Views: 625
Re: Quiz Preparation
It would be nice if they were provided right before the quizzes, so we could check our answers. This was done for 14B last year and I can see the quiz answers in my roommates old course reader from last year. That format worked much better than what we have now.
- Mon Jan 23, 2017 8:08 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Memorize Values for Quiz?
- Replies: 2
- Views: 568
Re: Memorize Values for Quiz?
No, they should be given.
- Sat Jan 21, 2017 5:21 pm
- Forum: Phase Changes & Related Calculations
- Topic: Practice Quizes
- Replies: 10
- Views: 1090
Re: Practice Quizes
Some students benefit by working with peers, but others (like me) are more successful working independently. I did very well last quarter on the quizzes with the provided answers. My only incentive was my grade so I refrained from going straight to the answers. I think the method last quarter was ve...
- Tue Jan 17, 2017 10:14 pm
- Forum: Phase Changes & Related Calculations
- Topic: Practice Quizes
- Replies: 10
- Views: 1090
Re: Practice Quizes
Would it be possible to get a PDF of the answers to the practice quizzes so we can study them at our own pace?
- Mon Jan 16, 2017 1:11 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Hess's Law
- Replies: 3
- Views: 505
Re: Hess's Law
When you need to cancel things from both sides. You switch signs to flip it.
for example:
A+B->C dH=x
2C->2A+D dH=y
you would multiply the top one by 2 to get A and C to cancel.
for example:
A+B->C dH=x
2C->2A+D dH=y
you would multiply the top one by 2 to get A and C to cancel.
- Wed Nov 30, 2016 6:58 pm
- Forum: *Indicators
- Topic: Selecting an indicator
- Replies: 4
- Views: 1582
Re: Selecting an indicator
So if the equivalence point is near pH 8, why wouldn't we want one that changes color near pH 8? How exactly did you get that range of pHs for the indicator?
- Wed Nov 30, 2016 3:50 am
- Forum: *Indicators
- Topic: Selecting an indicator
- Replies: 4
- Views: 1582
Selecting an indicator
Why does pKin. (pKA) have to be close to pH at stoichiometric point to be an effective indicator?
- Wed Nov 30, 2016 1:38 am
- Forum: DeBroglie Equation
- Topic: Fall 2012 Final Q1B
- Replies: 1
- Views: 411
Fall 2012 Final Q1B
For the equation that says:
p=hv/c -> 1pt of the grade
will h=pc/v also earn the point?
because both multiplied across -> pc=hv=E
p=hv/c -> 1pt of the grade
will h=pc/v also earn the point?
because both multiplied across -> pc=hv=E
- Mon Nov 28, 2016 11:06 pm
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: HW 12.47
- Replies: 1
- Views: 429
Re: HW 12.47
More oxygen=more electronegative, which stabilizes the negative charge on I, making it MUCH easier for the H to break off and protonate water to create hydronium, thus more acidic.
- Thu Nov 24, 2016 5:03 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: When Should I use the ICE table?
- Replies: 6
- Views: 18951
Re: When Should I use the ICE table?
You can approximate if you remember to check for the 5% rule after...to make sure you are within range.
- Wed Nov 16, 2016 10:10 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Why is He2 not a stable molecule?
- Replies: 1
- Views: 596
Re: Why is He2 not a stable molecule?
Exactly, you get a BO of 0. This means there is no bond, hence no stability as a molecule.
- Tue Nov 15, 2016 11:57 am
- Forum: Naming
- Topic: Partial Pressure
- Replies: 1
- Views: 366
Re: Partial Pressure
A decrease in partial pressure means a decrease in concentration, which would shift the rxn left. I don't think partial pressure vs pressure matters because because a decrease in pressure would cause the same effect.
- Sat Nov 12, 2016 3:04 pm
- Forum: Naming
- Topic: Naming Ligands
- Replies: 2
- Views: 557
Re: Naming Ligands
It is in an anionic complex.
K is a cation, so to make a neutral "salt" the [CoF6] must act as an anion and take a negative charge, hence cobaltate.
K is a cation, so to make a neutral "salt" the [CoF6] must act as an anion and take a negative charge, hence cobaltate.
- Tue Nov 01, 2016 10:12 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configuration for Fe 3+
- Replies: 6
- Views: 39038
Re: Electron Configuration for Fe 3+
Fe is [Ar]3d6 4s2
Fe2+ loses the 4s2
Fe3+ loses an electron from the d
so Fe3+ is [Ar]3d5
Not really an exception, just remember a full d/half full d will be much more stable(chromium/copper)
Fe2+ loses the 4s2
Fe3+ loses an electron from the d
so Fe3+ is [Ar]3d5
Not really an exception, just remember a full d/half full d will be much more stable(chromium/copper)
- Tue Nov 01, 2016 10:04 pm
- Forum: Hybridization
- Topic: Unhybridized Orbitals
- Replies: 2
- Views: 526
Re: Unhybridized Orbitals
Look at bonding.
For example, ethylene makes a C::C and each C also makes 2 H bonds, therefore each C makes a total of 3 bonds = sp2. When you look at sp3, which is the full octet, sp2 is missing a p, and that is your un hybridized p. This is where the pi bonding happens.
For example, ethylene makes a C::C and each C also makes 2 H bonds, therefore each C makes a total of 3 bonds = sp2. When you look at sp3, which is the full octet, sp2 is missing a p, and that is your un hybridized p. This is where the pi bonding happens.
- Tue Nov 01, 2016 5:19 pm
- Forum: Empirical & Molecular Formulas
- Topic: 2013 Midterm Q2A
- Replies: 1
- Views: 549
2013 Midterm Q2A
For this problem: I solved for moles of each element by taking the given values and dividing by their atomic masses. i.e.: Carbon 3.27g x 1molC/12.011gC = 0.272molesC then I divided by the smallest value, got the ratio, multiplied by a number to get rid of fractions to get the answer, found grams of...
- Tue Nov 01, 2016 5:10 pm
- Forum: Hybridization
- Topic: Fall 2012 Q6A [ENDORSED]
- Replies: 4
- Views: 697
Re: Fall 2012 Q6A [ENDORSED]
In the ring, the carbons each make two bonds, either to another carbon or to the nitrogen. Since the problem states hydrogens have been omitted and we know carbon likes to make 4 bonds, we would add in two hydrogens to each carbon to fulfill their octet. Therefore, each carbon actually makes 4 bonds...
- Mon Oct 31, 2016 12:07 am
- Forum: Hybridization
- Topic: Fall 2012 Q6A [ENDORSED]
- Replies: 4
- Views: 697
Fall 2012 Q6A [ENDORSED]
Hello, For this problem I don't understand how you find the hybridizations. Do we assume the carbon will just make two hydrogen bonds? Or is it possible it may form a double bond? Would we have to calculate FC and figure that out, or can we assume it will just get 2 H bonds as problem only states th...
- Mon Oct 24, 2016 11:59 pm
- Forum: Lewis Structures
- Topic: Lewis Structures wedge and dash
- Replies: 1
- Views: 1534
Lewis Structures wedge and dash
For example: SF6's wedge and dash depiction (page 95 of CR) we show the wedges towards us and the dashes away, but we draw lines for on the top and bottom. How do we determine which get wedge and dash, and which get solid lines. Alternatively, for CH4 how do we determine which get the wedge and dash...
- Mon Oct 24, 2016 11:54 pm
- Forum: Lewis Structures
- Topic: Octet Rule vs. Formal Charge
- Replies: 2
- Views: 562
Re: Octet Rule vs. Formal Charge
You want a formal charge of -1 because it is BrO-. The molecule should have a total formal charge of -1. Therefore it will make a single bond and each atom will have 3 lone pairs.
- Mon Oct 24, 2016 11:50 pm
- Forum: Lewis Structures
- Topic: workbook Quiz 2 preparation #7
- Replies: 3
- Views: 408
Re: workbook Quiz 2 preparation #7
The other oxygen should form a double bond as well. So you get Xe with a lone pair, both Fs single bonded with 3 lone pairs, and the 2 Os double bonded with 2 lone pairs. :O: .. || .. :F - Xe - F: .. || .. :O: This Lewis structure will give each atom a formal charge of 0 and will be the biggest cont...
- Mon Oct 17, 2016 4:46 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: SO4^2- Lewis Structure [ENDORSED]
- Replies: 1
- Views: 610
SO4^2- Lewis Structure [ENDORSED]
I understand that since S is in the n=3 -> l=0,1,2 meaning it can use the d orbital when bonding. However, in the example in class, we get 2 S double bonds with O and 2 S single bonds with 0, giving S 12 shared electrons, while the d orbital can hold 10. So what happens with the other 2 electrons no...
- Mon Oct 10, 2016 6:05 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Integrated Exercises on Infrared Spectroscopy
- Replies: 1
- Views: 502
Re: Integrated Exercises on Infrared Spectroscopy
To start off,
You should visualize it as v/c=3600cm^-1
then solve for v
that will give you a.
for b,
use the equation E=hv
and solve for E.
for c,
multiply the E from (b) by Avogadro's number to determine the energy for a mole.
You should visualize it as v/c=3600cm^-1
then solve for v
that will give you a.
for b,
use the equation E=hv
and solve for E.
for c,
multiply the E from (b) by Avogadro's number to determine the energy for a mole.
- Wed Oct 05, 2016 6:12 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: quiz 1 fall 2014 prep #10
- Replies: 4
- Views: 755
quiz 1 fall 2014 prep #10
Hello, I did #10 and I was looking at the answers in the back and noticed: "USE BOHR EQU. FOR H ATOM (ANY 1e- H-LIKE ATOM, Li^2+): En = -2.178x10^-18 J (Z^2/n^2) for n=1,2,3.... j=joules, z=atomic number, n=energy level" What is the difference between that equation and using -hR? When do w...
- Thu Sep 29, 2016 9:40 pm
- Forum: Properties of Electrons
- Topic: Kinetic Energy of Electrons [ENDORSED]
- Replies: 6
- Views: 10425
Re: Kinetic Energy of Electrons [ENDORSED]
I believe the formula finds the (minimum) energy needed to remove a single electron. Therefore, I think it is an increase in kinetic energy of a single electron.