Search found 22 matches
- Sat Mar 18, 2017 3:18 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: balancing half-reactions
- Replies: 1
- Views: 387
balancing half-reactions
When you have to reverse a half reaction, how do you know which one should be flipped? Is it the half-reaction with a lower cell potential?
- Sat Mar 18, 2017 1:25 am
- Forum: *Cyclohexanes (Chair, Boat, Geometric Isomers)
- Topic: substituents
- Replies: 1
- Views: 1377
substituents
Will all substituents have a preference for the equatorial position, as a general rule? I know that bigger substituents have a higher preference for the equatorial position, but will there ever be substituents that favor the axial position?
- Sat Mar 18, 2017 1:13 am
- Forum: *Cyclohexanes (Chair, Boat, Geometric Isomers)
- Topic: stability
- Replies: 1
- Views: 1176
stability
Is it more stable for there to be steric strain or torsional strain? Does it depend on the molecule?
- Fri Mar 17, 2017 11:13 pm
- Forum: *Cyclohexanes (Chair, Boat, Geometric Isomers)
- Topic: bond angle strain
- Replies: 1
- Views: 477
bond angle strain
Is bond angle strain only present when the C-C-C angle is anything other than 109.5? And the closer it is to 109.5, the less angle strain?
- Fri Mar 17, 2017 10:47 pm
- Forum: *Cyclopropanes and Cyclobutanes
- Topic: energy barriers
- Replies: 3
- Views: 1616
energy barriers
Is there an energy barrier that must be overcome for cyclobutane to move from one part of the butterfly conformation to the other, since it must briefly reassume a planar shape?
- Fri Mar 17, 2017 2:59 am
- Forum: *Alkanes and Substituted Alkanes (Staggered, Eclipsed, Gauche, Anti, Newman Projections)
- Topic: Electron Density and Conformations
- Replies: 1
- Views: 1436
Electron Density and Conformations
What role does electron density play in conformations? I know that the space filling model better shows electron density than other models, such as the ball and stick model, but what advantage does that have? Does changing conformation affect electron density?
- Fri Mar 17, 2017 2:15 am
- Forum: *Cycloalkanes
- Topic: Naming (from example in course reader)
- Replies: 1
- Views: 1236
Naming (from example in course reader)
On page 102 of the course reader, the name for 2-cyclopropyl-pentane is found from the given molecule. I understand how this conclusion was reached, but I do not understand why it is cyclopropyl instead of cyclopropane. So my question is this: what is the reasoning for inserting a -pyl suffix (just ...
- Wed Mar 08, 2017 2:43 am
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Catalyst vs. Intermediate Species
- Replies: 2
- Views: 1090
Re: Catalyst vs. Intermediate Species
An intermediate species is cancelled out in a multi-step reaction. For example, in a 2 step reaction if the product of Step One is a reactant in Step Two, then it is an intermediate. This is because does not appear in the initial reactants or final products. Catalysts, in contrast, provide a new pat...
- Tue Jan 31, 2017 11:09 am
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: work
- Replies: 2
- Views: 570
Re: work
The equation w=PdeltaV is used when there is a constant pressure when calculating work. The equation w=-nRTln(V2/V1) is used when there is constant temperature.
- Sun Jan 29, 2017 3:56 pm
- Forum: Calculating Work of Expansion
- Topic: Work Equation Derivation
- Replies: 1
- Views: 471
Re: Work Equation Derivation
You use w=-P(external) x V when there is constant pressure, and you use w=-nRT x ln (Vfinal/Vinitial) when there is constant temperature (isothermal); when there is constant volume, w=0
- Wed Jan 11, 2017 7:02 pm
- Forum: Calculating Work of Expansion
- Topic: Thermodynamics: The First Law
- Replies: 1
- Views: 491
Re: Thermodynamics: The First Law
You would use the formula Q=m(deltaT) because you are trying to find Q without a phase shift. If there was a phase shift, such as from water to water vapor, then you would need to use Q=m(c)(deltaT) formula.
- Thu Dec 01, 2016 7:25 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3612903
Re: Post All Chemistry Jokes Here
What kind of fruit did Avogadro eat in the summer?
WaterMOLEns
WaterMOLEns
- Mon Nov 28, 2016 2:21 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Equilibrium concentrations
- Replies: 1
- Views: 381
Equilibrium concentrations
Are ICE tables only used for weak acids or bases? So how would you calculate pH of a strong acid? Would you just take the negative log of the initial molarity? If so, what is the reasoning behind that?
- Fri Nov 18, 2016 3:09 pm
- Forum: Sigma & Pi Bonds
- Topic: Bond Strength [ENDORSED]
- Replies: 2
- Views: 1330
Re: Bond Strength [ENDORSED]
sigma bonds are not single bonds, and pi bonds are not double bonds. a single bond has one sigma bond, a double bond has one sigma and one pi bond, and a triple bond has one sigma and two pi bonds.
- Sun Nov 13, 2016 6:53 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Partial Pressure or Concentration
- Replies: 3
- Views: 743
Re: Partial Pressure or Concentration
You solve for Kp when dealing with a gaseous reaction. You solve for Kc when dealing with any other reaction (but only include aqueous components in your K expression). Hope this helps!
- Thu Nov 03, 2016 7:15 pm
- Forum: Sigma & Pi Bonds
- Topic: MO bonding notation
- Replies: 1
- Views: 475
Re: MO bonding notation
nope, but we need to know it for the final
- Thu Nov 03, 2016 7:12 pm
- Forum: Hybridization
- Topic: Dipole Moment
- Replies: 2
- Views: 739
Re: Dipole Moment
it does depend on electronegativity, and the arrow points to the MORE electronegative atom. formal charge is not a determining factor here
- Thu Oct 27, 2016 9:39 pm
- Forum: Sigma & Pi Bonds
- Topic: hybridization with sigma and pi bonds
- Replies: 1
- Views: 504
hybridization with sigma and pi bonds
would it be safe to assume that sp3 hybridization corresponds to single bonds, sp2 hybridization to double bonds, and sp1 to triple bonds in a general sense?
- Fri Oct 21, 2016 1:34 pm
- Forum: Ionic & Covalent Bonds
- Topic: Drawing Lewis structures
- Replies: 1
- Views: 515
Drawing Lewis structures
How many bonds are in H3O+ ? I can't figure out a way to draw this structure while following the octet rule. Since H can only bond once, you can't make any double bonds. But since this is an ion with one less electron, you are left with a singule electron that is not bonded on the O, which you can't...
- Wed Oct 12, 2016 2:59 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Quantum Numbers n, l, and m
- Replies: 2
- Views: 553
Re: Quantum Numbers n, l, and m
Okay so to answer your questions... 1) yes; if you look in the course reader, that is exactly how they are labelled 2) if i understand your question, then yes; l assigns a value (referred to as subshell) to each orbital (s, p, d, or f) and the highest l value, say l=4, will contain not only the f-or...
- Thu Oct 06, 2016 4:43 pm
- Forum: Balancing Chemical Reactions
- Topic: Naming Compounds
- Replies: 2
- Views: 904
Re: Naming Compounds
If by compounds you mean polyatomic ions, then yes! A good rule of thumb is to start by remembering that almost all of them have negative charges; it's a lot easier to remember the few exceptions (like ammonium) that way. Other than that, it's pretty much memorization. As you study them, you should ...
- Wed Sep 28, 2016 11:14 pm
- Forum: Properties of Light
- Topic: Unique Frequencies with atoms/molecules
- Replies: 3
- Views: 969
Re: Unique Frequencies with atoms/molecules
How does electrical field correspond to amplitude? I'm not quite sure of the relationship here.