Search found 25 matches

by Jenny_Thompson_3I
Sat Mar 18, 2017 9:41 am
Forum: *Cyclohexanes (Chair, Boat, Geometric Isomers)
Topic: substituents
Replies: 1
Views: 329

Re: substituents

In most cases, substituents favor the equatorial position because it leads to more stability of the molecule overall. For example, when substituents are in the axial position it can lead to steric strain with the other axial molecules, which makes the structure less stable.
by Jenny_Thompson_3I
Sat Mar 11, 2017 2:10 pm
Forum: *Calculations Using ΔG° = -RT ln K
Topic: Chem 14b final
Replies: 2
Views: 472

Re: Chem 14b final

The final will be from 3pm - 6pm and the rooms will be released soon
by Jenny_Thompson_3I
Sun Mar 05, 2017 1:20 pm
Forum: *Electrophiles
Topic: CH3Cl
Replies: 2
Views: 497

Re: CH3Cl

It is because of the fact that the C-Cl bond is polar. Since Cl is negative, the electrons will be more drawn to that atom so a dipole moment will occur. The Cl will be slightly negative and the C will be slightly positive, this is what makes it and electrophile. Since the C carries a slight positiv...
by Jenny_Thompson_3I
Sat Feb 25, 2017 10:25 am
Forum: *Organic Reaction Mechanisms in General
Topic: Nucleophiles
Replies: 2
Views: 292

Re: Nucleophiles

Many times it depends on the formal charge of the central atom. If the formal charge is negative then the species will be a nucleophile and will be attracted to positively charged particles.
by Jenny_Thompson_3I
Sat Feb 18, 2017 10:12 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7337
Views: 825509

Re: Post All Chemistry Jokes Here

"Did you know that you can cool yourself to -273.15˚C and still be 0k?" "Helium walks into a bar, The bartender says "We don't serve noble gasses in here." Helium doesn't react." "The optimist sees the glass half full. The pessimist sees the glass half empty. The c...
by Jenny_Thompson_3I
Sat Feb 11, 2017 11:13 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Positive or negative Ecell
Replies: 2
Views: 2955

Re: Positive or negative Ecell

You determine the Ecell value from the two half reactions you write from either the cell diagram given or the balanced chemical equation. The formula for calculating the Ecell is E(cathode) - E(anode) and these values you get from the chart of standard E values that is found in the back of the book....
by Jenny_Thompson_3I
Sun Feb 05, 2017 2:07 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Porous Disk
Replies: 2
Views: 551

Re: Porous Disk

A salt bridge is when you have two different solutions that are in different beakers while a porous disc is used in a concentration cell in which you have two solutions that are the same but are at different molarities. Also, a porous disc is used when there is only one beaker while a salt bridge is...
by Jenny_Thompson_3I
Sat Jan 28, 2017 10:31 am
Forum: Calculating Work of Expansion
Topic: Reversible and Irreversible processes
Replies: 1
Views: 243

Re: Reversible and Irreversible processes

A reaction that is reversible occurs when the external and internal pressures are the same and the system is at equilibrium (for example 1.00 atm), therefore when the system expands it does so when there are extremely small changes in the external pressure that is reestablished when the system expan...
by Jenny_Thompson_3I
Sat Jan 21, 2017 11:07 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Degeneracy [ENDORSED]
Replies: 3
Views: 474

Re: Degeneracy [ENDORSED]

Since O2 is a diatomic molecule it is impossible to know whether or not the O molecules are changing positions, thus giving us w=1. And the ln(1) is 0, which them means the S=0 so there is no change in entropy.
by Jenny_Thompson_3I
Thu Jan 12, 2017 3:49 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Enthalpy sign changes
Replies: 2
Views: 239

Re: Enthalpy sign changes

For a reaction that is exothermic it will have a negative enthalpy since it is releasing energy. A reaction that is endothermic will have a positive enthalpy since it is absorbing energy.
by Jenny_Thompson_3I
Tue Nov 29, 2016 3:30 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 12.61
Replies: 4
Views: 518

Re: 12.61

To solve this question you are still using an ICE box but you are working backwards in order to find the concentration of HClO. Since you are given the pH you can find the concentration of H3O+ and then use that information to find the concentration of HClO.
by Jenny_Thompson_3I
Fri Nov 25, 2016 1:53 pm
Forum: Bronsted Acids & Bases
Topic: Weak Acid
Replies: 4
Views: 534

Re: Weak Acid

HF is a weak acid due to the fact that it has a short and strong bond. For example HI is a stronger acid due to the fact that it has a large atomic radius and a short bond length, making it easier to break apart. Since HF has a smaller atomic bond it has a longer bond length making it more difficult...
by Jenny_Thompson_3I
Wed Nov 16, 2016 9:22 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: what is the concentration
Replies: 1
Views: 189

Re: what is the concentration

For this you need to set up the ICE box that was described in the course reader and lecture and the solve for x using the quadratic equation.
by Jenny_Thompson_3I
Sun Nov 13, 2016 2:28 pm
Forum: Naming
Topic: Atoms Outside of the Coordination Complex
Replies: 1
Views: 230

Re: Atoms Outside of the Coordination Complex

The atoms that are outside the coordination complex do not have any effect on the coordination number. With the example you gave the charge for the coordination complex is +2 and the charge of each K is +1, so the 2 K atoms create an compound with an overall charge of 0. The coordination complex and...
by Jenny_Thompson_3I
Thu Nov 03, 2016 10:51 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Bonding vs Antibonding
Replies: 3
Views: 429

Re: Bonding vs Antibonding

The difference between bonding and antibonding is determined from whether or not the molecular orbital is in phase or out of phase. In phase will produce bonding while out of phase will produce antibonding. The phase is determined from the molecular wave function that is a linear combination of two ...
by Jenny_Thompson_3I
Thu Oct 27, 2016 5:52 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Presence of Lone Pairs [ENDORSED]
Replies: 2
Views: 279

Re: Presence of Lone Pairs [ENDORSED]

You want the lone pair electrons to be as far away from each other, so for example if you have two sets of lone pairs they would be 180 degrees apart from each other. For just one lone pair, it does not really make to much of a difference where you place the electrons because the lone pair will be a...
by Jenny_Thompson_3I
Thu Oct 20, 2016 3:23 pm
Forum: Electronegativity
Topic: Units for electronegativity
Replies: 4
Views: 854

Re: Units for electronegativity

Electronegativity is calculated by using both electron affinity and ionization energy, so it is not a value that is calculated from an experiment. Since it is not a measured quality, it does not have units. Hope this helps!
by Jenny_Thompson_3I
Wed Oct 12, 2016 1:53 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Minimum Indeterminacy [ENDORSED]
Replies: 6
Views: 899

Re: Minimum Indeterminacy [ENDORSED]

Another note to this when you are imputing the velocity into the equation you need to multiply it by 2 due to the fact that there is a +/- sign in front of it. This will account for both the positive and negative uncertainty of the velocity.
by Jenny_Thompson_3I
Fri Oct 07, 2016 8:26 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: D orbital shapes [ENDORSED]
Replies: 1
Views: 332

Re: D orbital shapes [ENDORSED]

The difference between the d(xy) and d(x^2, y^2) is what axis the orbitals lay on in a three dimensional space. This changes the orientation and direction of the orbital. The x, y, and z axis are used to describe which planes the orbitals lie in.
by Jenny_Thompson_3I
Wed Oct 05, 2016 9:46 am
Forum: DeBroglie Equation
Topic: Measurable Wavelength (baseball) [ENDORSED]
Replies: 1
Views: 312

Re: Measurable Wavelength (baseball) [ENDORSED]

Since the wavelength produced by the baseball's movement is so small, there is now way that we can detect this wavelength. The baseball is technically producing a wave, but it is impossible to detect. We are able to detect the wavelike properties of an election due to the fact that it is so small, w...
by Jenny_Thompson_3I
Fri Sep 30, 2016 7:55 am
Forum: Properties of Light
Topic: Increasing Intensity in Photoelectric Effect [ENDORSED]
Replies: 9
Views: 906

Re: Increasing Intensity in Photoelectric Effect [ENDORSED]

The main concept was that Dr. Lavelle said that increasing the intensity of white light (the light source) does not lead to electrons being removed. In order to remove electrons from the metal you must have a light source with a shorter wavelength. Then in your increase the intensity of this shorter...
by Jenny_Thompson_3I
Fri Sep 30, 2016 7:49 am
Forum: General Science Questions
Topic: Rusty on High School Chem [ENDORSED]
Replies: 113
Views: 36242

Re: Rusty on High School Chem [ENDORSED]

I also took AP Chemistry my sophomore year so I would recommend doing this. Going through the homework problems and working them all along with reading the text book. Any questions you have on the homework problems, I would go to office hours and ask the TA/UA for help and he/she can walk you throug...
by Jenny_Thompson_3I
Thu Sep 29, 2016 10:58 am
Forum: Limiting Reactant Calculations
Topic: Homework Problem M.19 Help
Replies: 4
Views: 538

Re: Homework Problem M.19 Help

Thank you Megan! That was extremely helpful and I though that was the path I should go on so thank you for confirming.
by Jenny_Thompson_3I
Wed Sep 28, 2016 2:32 pm
Forum: Administrative Questions and Class Announcements
Topic: Chem Workbook
Replies: 1
Views: 312

Chem Workbook

Are the quizzes that are provided in the Chem Workbook due to our TA's before we take each quiz and can you actually replace a quiz grade from the quizzes taken from the Chem Workbook?
by Jenny_Thompson_3I
Wed Sep 28, 2016 2:29 pm
Forum: Limiting Reactant Calculations
Topic: Homework Problem M.19 Help
Replies: 4
Views: 538

Homework Problem M.19 Help

For problem M.19 I am having trouble figuring out where to start due to the fact that it only gives the amounts of carbon dioxide, water, and nitrogen for the products. Are we to just assume that caffeine is composed of carbon, oxygen, hydrogen, and nitrogen and then work backwards using the masses ...

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