CHEMISTRY COMMUNITY

Alyssa Chan 3B

When we name an organic molecule with a double bond, do we always have to identify where the double bond is located?

Alyssa Chan 3B

Alyssa Chan 3B

#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...

Alyssa Chan 3B

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...

Alyssa Chan 3B

Since both pressure and volume are changing (implying constant temp), you would use the equation W = -nRT $\ln\frac{Vf}{Vi}$ . For all reversible reactions, ∆U = 0. You can use these two equations to solve for w, q, and ∆U.

Alyssa Chan 3B

At constant pressure, why is C_p (s) > C_p (l) > C_p (g) for the phase change of water?

Alyssa Chan 3B

Organic chemistry is difficult. Those who study it have alkynes of trouble.

Alyssa Chan 3B

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,...

Alyssa Chan 3B

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...

Alyssa Chan 3B

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.

Alyssa Chan 3B

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!

Alyssa Chan 3B

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!

Alyssa Chan 3B

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...

Alyssa Chan 3B

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?

Alyssa Chan 3B

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...

Alyssa Chan 3B

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...

CHEMISTRY COMMUNITY

Search found 16 matches

Naming Convention for Double Bonds

Re: Post All Chemistry Jokes Here

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

Re: Quiz One - #5 Calculating Heat

Re: Quiz 1 Prep Question 3

Molar Heat Capacity for Phase Change of Water

Re: Post All Chemistry Jokes Here

Weak Acid Titration Equilibrium Table Equation? [ENDORSED]

Re: Fall 2014 Quiz Prep #8

Re: Clarification on R and P Calculations

What is a Ligand?

Workbook: Quiz 2 Prep #4

Re: Lewis Structure regarding the angles

Question about Uncertainty in Velocity [ENDORSED]

Re: Ch. 1 HW #33c

Clarification for G.7