Search found 16 matches

by Alyssa Chan 3B
Thu Mar 16, 2017 8:47 pm
Forum: *Alkenes
Topic: Naming Convention for Double Bonds
Replies: 1
Views: 326

Naming Convention for Double Bonds

When we name an organic molecule with a double bond, do we always have to identify where the double bond is located?
by Alyssa Chan 3B
Wed Mar 08, 2017 10:47 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7337
Views: 787696

Re: Post All Chemistry Jokes Here

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by Alyssa Chan 3B
Tue Feb 14, 2017 3:41 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Winter 2013 Midterm #7: Which Nernst Equation to Use?
Replies: 2
Views: 252

Winter 2013 Midterm #7: Which Nernst Equation to Use?

#7 of the Winter 2013 practice midterm uses the Nernst equation E = E˚ - \frac{0.05916V}{n} logQ to solve for K. Why isn't the other equation E = E˚ - \frac{RT}{nF} lnQ used? When I used the second equation, the answer wasn't the same as when I used the first. How do you know when to use which equat...
by Alyssa Chan 3B
Sat Feb 11, 2017 5:25 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Quiz One - #5 Calculating Heat
Replies: 2
Views: 284

Re: Quiz One - #5 Calculating Heat

I think we have the same quiz--melting a -55˚C block of ice into 25˚C water? When you first melt ice from -55˚to 0˚, you use the specific heat capacity of ice in the equation q = mc∆T. During the phase change from ice to water (at 0˚), you use the heat of fusion in the equation q = n∆H fus (note tha...
by Alyssa Chan 3B
Thu Jan 26, 2017 11:03 am
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Quiz 1 Prep Question 3
Replies: 4
Views: 555

Re: Quiz 1 Prep Question 3

Since both pressure and volume are changing (implying constant temp), you would use the equation W = -nRT. For all reversible reactions, ∆U = 0. You can use these two equations to solve for w, q, and ∆U.
by Alyssa Chan 3B
Wed Jan 25, 2017 12:12 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Molar Heat Capacity for Phase Change of Water
Replies: 1
Views: 213

Molar Heat Capacity for Phase Change of Water

At constant pressure, why is Cp (s) > Cp (l) > Cp (g) for the phase change of water?
by Alyssa Chan 3B
Mon Jan 16, 2017 12:09 am
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7337
Views: 787696

Re: Post All Chemistry Jokes Here

Organic chemistry is difficult. Those who study it have alkynes of trouble.
by Alyssa Chan 3B
Sat Dec 03, 2016 7:49 pm
Forum: *Titrations & Titration Calculations
Topic: Weak Acid Titration Equilibrium Table Equation? [ENDORSED]
Replies: 1
Views: 356

Weak Acid Titration Equilibrium Table Equation? [ENDORSED]

When you're trying to find the pH at the stoichiometric point of a titration of a weak acid and a strong base, why do you use the reaction between the salt and H 2 O as the chemical equation for the equilibrium table? Why don't you use the reaction between the weak acid and strong base? For example,...
by Alyssa Chan 3B
Tue Nov 15, 2016 12:42 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Fall 2014 Quiz Prep #8
Replies: 1
Views: 234

Re: Fall 2014 Quiz Prep #8

You don't need to use PV=nRT for this problem! :) Just use the ICE table Since you already set the equilibrium constant expression, I'm assuming you got: K p = P NH3 (P H2S ) = 0.11 Using the ICE table, you would ignore NH 4 HS (because it's a solid) and just focus on NH 3 & H 2 S Initial partia...
by Alyssa Chan 3B
Sat Nov 12, 2016 2:12 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Clarification on R and P Calculations
Replies: 2
Views: 210

Re: Clarification on R and P Calculations

The brackets indicate the molar concentrations of the R and P, not molar masses.
Kp measures equilibrium for gas pressures, so you use the partial pressures of R and P.

Solids and liquids aren't included in the equilibrium calculations because their molar concentrations don't change in a reaction.
by Alyssa Chan 3B
Sat Nov 12, 2016 1:48 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: What is a Ligand?
Replies: 3
Views: 692

What is a Ligand?

I'm not sure what exactly a ligand is. Is it just any atom attached to a central atom of a molecule? Or is a ligand specifically a transition metal, polyatomic ion, etc?

Thank you!
by Alyssa Chan 3B
Tue Oct 25, 2016 12:22 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Workbook: Quiz 2 Prep #4
Replies: 3
Views: 393

Workbook: Quiz 2 Prep #4

For the electron configuration of Cl - using noble gas abbreviation, should it be [Ne] 3s 2 3p 6 or simply [Ar]? My high school AP chem teacher taught me the first is the correct configuration and the second is not quite correct. Should the configuration be using [Ne] or are both correct? Thank you!
by Alyssa Chan 3B
Fri Oct 21, 2016 4:09 pm
Forum: Lewis Structures
Topic: Lewis Structure regarding the angles
Replies: 2
Views: 288

Re: Lewis Structure regarding the angles

In class, Dr. Lavelle used the example of BF 3 for a trigonal planar structure. For your case, let's say one of the F atoms is Cl. Since Cl is a bigger atom than F (thus more repulsion), it would cause the angle between the Cl and F atoms to become bigger. Knowing that the angle between atoms of a t...
by Alyssa Chan 3B
Tue Oct 11, 2016 3:27 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Question about Uncertainty in Velocity [ENDORSED]
Replies: 1
Views: 280

Question about Uncertainty in Velocity [ENDORSED]

When a problem says that ∆v is ± ____ m/s, why do you multiply the ∆v value by 2 when you're solving the uncertainty equation?
by Alyssa Chan 3B
Mon Oct 10, 2016 4:09 pm
Forum: Photoelectric Effect
Topic: Ch. 1 HW #33c
Replies: 1
Views: 253

Re: Ch. 1 HW #33c

The answer you found for part b, E = 1.66 x 10 -17 J, is the work function (threshold energy). In part c, you're trying to find the energy of the photon, which is: E photon = work function (threshold energy) + E k Plug in the answer from part b in to the the work function, and plug in the mass and v...
by Alyssa Chan 3B
Sat Oct 01, 2016 11:23 am
Forum: Molarity, Solutions, Dilutions
Topic: Clarification for G.7
Replies: 2
Views: 340

Clarification for G.7

You need to prepare 510. g of an aqueous solution containing 5.45% KNO3 by mass. Describe how you would prepare the solution and what mass of each component you would use. Is the question saying that there is 510. g of substance that is dissolved into solution? Or is 510. g of solution is measured o...

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