Search found 17 matches

by Christine Rae 1I
Fri Mar 11, 2016 4:58 pm
Forum: *Cyclohexanes (Chair, Boat, Geometric Isomers)
Topic: Equatorial Priority
Replies: 1
Views: 604

Re: Equatorial Priority

The larger substituent will have a greater preference towards the equatorial position because it is more stable. For instance, in cis-1-propyl-3-methylcyclohexane, the propyl would be in the equatorial position because it is the larger and more bulky substituent, while the methyl would be in the axi...
by Christine Rae 1I
Sun Mar 06, 2016 9:59 pm
Forum: *Alkanes and Substituted Alkanes (Staggered, Eclipsed, Gauche, Anti, Newman Projections)
Topic: Torsional Strain vs Steric Strain
Replies: 1
Views: 368

Re: Torsional Strain vs Steric Strain

Steric strain cannot be lessened by rotating a molecule around the bond, while torsional strain is the force that opposes rotation of a part of a molecule about a bond. Thus, steric strain has to do with the atoms/molecules connected to bonds and the space they take up while torsional strain is more...
by Christine Rae 1I
Thu Feb 25, 2016 9:43 pm
Forum: *Alkanes
Topic: Drawing Structures
Replies: 4
Views: 413

Re: Drawing Structures

I have another question in regards to numbering the carbons and how they are inserted in the name of the molecule. If we had two constituents placed on carbons that had the same lowest numbers from left to right or right to left (such as pentane with different hydrocarbon substituents on 2nd and 4th...
by Christine Rae 1I
Wed Feb 17, 2016 12:51 am
Forum: Zero Order Reactions
Topic: Plots
Replies: 2
Views: 466

Re: Plots

To be more specific, look for a straight line when you plot the experimental data. different axes correspond to the different orders, zero order, first order, and second order, respectively: [A] vs. time (N=0), ln[A] vs. time (N=1), or 1/[A] versus time (N=2). The graph with the straight line will h...
by Christine Rae 1I
Sun Feb 14, 2016 9:56 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Rates of Reactions
Replies: 2
Views: 415

Re: Rates of Reactions

We want to work with positive with reaction rates, and -d[R]/dt=d[P]/dt means that the concentration of reactants at a certain time is decreasing while the concentration of products is increasing at a certain time. This is for the forward reaction rate. I believe moving the negative sign would be re...
by Christine Rae 1I
Sun Feb 07, 2016 6:37 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Using Pt in Cell Diagrams
Replies: 1
Views: 271

Re: Using Pt in Cell Diagrams

You use Pt(s) when there is no solid anode/cathode given in the 1/2 reactions.
by Christine Rae 1I
Sun Jan 31, 2016 9:30 am
Forum: Balancing Redox Reactions
Topic: Memory tool for Oxidation and Reduction
Replies: 1
Views: 316

Re: Memory tool for Oxidation and Reduction

Thanks Emma! Another one I know from high school is LEO (Loses Electrons -Oxidized) says GER (Gains Electrons Reduced).
by Christine Rae 1I
Sun Jan 24, 2016 10:09 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Reversible and Isothermal
Replies: 2
Views: 516

Re: Reversible and Isothermal

In isothermal systems there is a change while the temperature remains constant, so deltaT = 0.
The temperature isn't changing and there is no kinetic energy between particles so the internal energy is 0.
Therefore, deltaU = 0.
Because deltaU = 0 = q +w
q = -w

hope this helps
by Christine Rae 1I
Sun Jan 17, 2016 5:32 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: internal energy (u)
Replies: 2
Views: 260

internal energy (u)

In a system under constant pressure, if delta U is zero, why does the volume of gas still increase?
by Christine Rae 1I
Fri Jan 08, 2016 8:07 pm
Forum: Phase Changes & Related Calculations
Topic: Exothermic vs. Endothermic
Replies: 8
Views: 2301

Exothermic vs. Endothermic

In Monday's lecture Professor Lavelle made a verbal example about a knee and ice pack that left me confused. If the ice pack is considered as the system and a person's knee is the surroundings... Is this considered endothermic because the knee [surroundings] cools down and the ice pack's [system] en...
by Christine Rae 1I
Sun Dec 06, 2015 11:35 am
Forum: *Titrations & Titration Calculations
Topic: weak acid
Replies: 1
Views: 257

weak acid

At Prof Lavelle's review session he reviewed a problem "calculate the pH at the stoichiometric point of titration of 25.oo ml of .100 M HCOOH with .150 NaOH ka=1.8x10^-4" Why do you assume that the concentration of anion is equal to the initial concentration weak acid when calculating the ...
by Christine Rae 1I
Sun Nov 15, 2015 11:25 pm
Forum: Naming
Topic: Naming coordination compounds
Replies: 1
Views: 214

Naming coordination compounds

My question is about naming [Fe(CN)6]^4-
Why is it named hexacyanoferrate(III)ion and not hexacyanidoferrate(III)ion
when CN- is cyanido in the book??
Thanks in advance!
by Christine Rae 1I
Sun Nov 01, 2015 11:42 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Heteronuclear Diatomic Molecules
Replies: 1
Views: 538

Re: Heteronuclear Diatomic Molecules

Electronegativity is the electron pulling power of an atom, and an atom with a higher electronegativity will pull the shared electrons pair more towards itself. This is true for bonding orbitals, where the more electronegative atom will dominate. However, this is not true for antibonding orbitals. F...
by Christine Rae 1I
Sun Oct 25, 2015 11:41 pm
Forum: Hybridization
Topic: Benzene Hybridization and Stability
Replies: 2
Views: 546

Re: Benzene Hybridization and Stability

In benzene there are 12 sigma bonds and 3 pi bonds. In sigma bonds, the electrons are allowed to rotate. Thus, the shared electrons in benzene are delocalized, or in other words, they do not have a specific location in the molecule. This contributes to benzene's resonance, and thus, the stability of...
by Christine Rae 1I
Sun Oct 18, 2015 6:52 pm
Forum: Ionic & Covalent Bonds
Topic: Bond Strength
Replies: 2
Views: 463

Re: Bond Strength

Hi! What really helped me understand this excerpt in the reading was the graph on the top right corner (Figure 3.15). So basically, the graph is plotted with energy versus internuclear distance (the distance between the nuclei). The graph relates those two variables together, and the distance of the...
by Christine Rae 1I
Sun Oct 11, 2015 11:56 pm
Forum: Lewis Structures
Topic: Lewis Structure Exceptions
Replies: 1
Views: 454

Re: Lewis Structure Exceptions

Hi, hopefully this might help a little bit because I was confused too. B + 3F = 3e- + 3(7e-) = 24e- So to set up the Lewis structure, Boron should be in the center because it has the lowest ionization energy. Where as fluorine atom is looking to gain an electron to reach the octet rule. On page 60 o...
by Christine Rae 1I
Fri Oct 02, 2015 10:59 pm
Forum: DeBroglie Equation
Topic: De Broglie Equation in terms of Light
Replies: 2
Views: 507

Re: De Broglie Equation in terms of Light

In today's lecture, Prof Lavelle discussed how the De Broglie equation should be used to calculate wavelength for things that have rest mass (have mass in general). A photon, or a packet of light, has no rest mass, since it is just a unit of energy.

I hope this helps!

Go to advanced search