CHEMISTRY COMMUNITY

Chin_Alyssa_3I

How did you know that Step 2 was the slow/rate-limiting step? Why couldn't it be step 1?

Chin_Alyssa_3I

To Dr. Lavelle, the TAs and UAs: Thank you all for your time and dedication to the class. The quality of the teaching was top-notch and all the resources outside of class from Chemistry Community, to Peer learning sessions, to office hours, has all been tremendously helpful. It has been an honor to ...

Chin_Alyssa_3I

From Part A, I got the equilibrium constant to be .676.

Considering the Standard change in Gibbs Free Energy formula, with a positive K and positive T then the free energy would be negative and thus the reaction would be exothermic. However the answer is endothermic. Why?

Chin_Alyssa_3I

I was wondering for number six on the actual quiz 2 we took in our discussion, why Step 1 was the slow step and not Step 2?

Chin_Alyssa_3I

Chin_Alyssa_3I

ntyshchenko wrote:What about Lecture 2s video?

Lecture 2 does not have a video because it is not filmed. Only lecture 3 is filmed

Chin_Alyssa_3I

I want to post a joke, but all the good ones Ar (Argon)

Chin_Alyssa_3I

As I am going over past midterms in the course reader I noticed that for certain problems points are deducted for not having the correct sig figs, while for other problems, sig figs were not taken into account for the total points. I was wondering for this midterm if sig figs will be a part of our t...

Chin_Alyssa_3I

In class on Monday we went over page 59 in the course reader where Dr. Lavelle went over the reaction rates and derived a "formula" for us to follow when setting up the rates. In the process of the derivation, he multiply the d[O2]/dt by 2 but not for d[NO]/dt and -d[NO2]/dt. Shouldn't it ...

Chin_Alyssa_3I

Q: Your very particular friend Sheldon asks for a glass of exactly 400g of water at 16 C. You can get liquid water at room temperature from the faucet and ice at 0C from the freezer. How many grams of ice and how many grams of water must you combine to make Sheldon's very specific water? The only pa...

Chin_Alyssa_3I

How do you know when to use Kelvin or Celsius in a problem? Can you just always use and convert a question to Kelvin? How you know which unit to use is really dependent on the rest of the values in your problem and their units. Use the other values and units as a guide to help you determine whether...

Chin_Alyssa_3I

what do we use the green course reader for? I do not understand the difference between the torquoise and the green course readers we received from the course reader store. I believe that the green course reader starts covering organic chemistry, which I believe we will start to go over later in the...

Chin_Alyssa_3I

8.85 The oxidation of nitrogen in the hot exhaust of jet engines and automobiles occurs by the reaction N2 (g) + O2 (g) -> 2 NO(g) H°=180.6 kJ (a) How much heat is absorbed in the formation of 1.55 mol NO? (b) How much heat is absorbed in the oxidation of 5.45 L of nitrogen measured at 1.00 atm an...

Chin_Alyssa_3I

What is the Kekulé structure that is referred to in problem 77 of chapter 8?

Chin_Alyssa_3I

8.65 Calculate the standard enthalpy of formation of dinitrogen pentoxide from the following data, 2 NO(g) + O2 (g) -> 2NO2(g) H°= -114.1 kJ 4 NO2(g) + O2(g) -> 2 N2O5(g) H°= -110.2 kJ and from the standard enthalpy of formation of nitric oxide, NO (see Appendix 2A). At first I approached it using ...

Chin_Alyssa_3I

Why do chemists learn about ammonia first?

...

Cause it's pretty basic stuff

Chin_Alyssa_3I

This is a general question for when calculating. Do we still take into account sig figs when we give our final answer? As I do the textbook problems and compare the answers, I noticed that the answers in the textbook for pH and pOH are always rounded off to 2 decimal places regardless of the sig fig...

Chin_Alyssa_3I

11.87 Dissociation of a diatomic molecule, X2(g) -> 2 X(g) occurs at 500 K. Picture 1 shows the equilibrium state of the dissociation and picture 2 shows the equilibrium state in the same container after a change has occurred. Which of the following changes will produce the change shown? (a) Increas...

Chin_Alyssa_3I

11.73 State whether reactants or products will be favored by an increase in the total pressure (resulting from compression) on each of the following equilibria. If there is no change, explain why that is so. (b) H2O(g) + C(s) ↔ H2(g) + CO(g) Since there are 2 moles on both sides, I thought that ther...

Chin_Alyssa_3I

Thank you for your reply! However in the course reader on page 117 there is an asterisk next to nitrito and the asterisk indicates which ligands are polydentates, as stated on the bottom of the diagram...So is that an error...?

Chin_Alyssa_3I

I know that when you go from FORMULA to the NAME, the ligands must be in alphabetical order. However when you go from NAME to FORMULA, I noticed the metal comes first but is there a particular order for the ligands? Also I know that nitrito is a polydentate but specifically is it a bidentate? (Coord...

Chin_Alyssa_3I

In class Professor Lavelle mentioned that the detailed solutions were posted online. However I couldn't hear what he said afterwards so I was wondering if he stated exactly where. I can't seem to find it on Chem Community or the Class website.

Chin_Alyssa_3I

I noticed that sometimes the constant values given in our notes/course reader does not exactly match the laminated periodic table we received with the course reader. For example, h=6.626E-34 in our reader but is more specifically stated as h=6.62608E-34 on the periodic table Also c=3.00E8 vs c=2.997...

Chin_Alyssa_3I

I was wondering for the sp^2 hybridization if there is always an unhybridize p orbital that forms a pi bond or is that just the case for the Carbon atom because of its potential double bonds. How about for B? Would B have an unhybridize p orbital? How would you know or solve for the difference?

Chin_Alyssa_3I

I have a lecture right before this midterm so I will not have time to go back to the hill to drop off my backpack, my phone, and all my books. May I bring my backpack into the testing room and leave it in the front and/or with the test proctor? If not, is there anywhere else I can store my stuff?

Chin_Alyssa_3I

CATions

An ion with a PAWS-itive charge

Chin_Alyssa_3I

So let's say you want to calculate the Electronegativity Difference of CH4... ( C = 2.6 ; H = 2.2 )

Would the answer just be .4 or do you have to multiply 2.2 by 4 since there are 4 H atoms and then subtract by 2.6?

Chin_Alyssa_3I

Find the uncertainty in the position of a marble of bass 1.5 g given that its speed is known to within plus or minus .55 m/s

My question is whether the uncertainty in velocity is .55 or is it the difference...(.55 - -.55 = 1.10)?

Chin_Alyssa_3I

1.15 In the ultraviolet spectrum of atomic hydrogen, a line is observed at 102.6 nm. Determine the values of n for the initial and final energy levels of the electron during the emission of energy that leads to this spectral line. [sol] Since it is a Lyman series, I know that nf (n final) is 1. I al...

Chin_Alyssa_3I

Where did you get 1 meter from?

Chin_Alyssa_3I

Thank you so much!

Chin_Alyssa_3I

M.5 Solve this exercise without using a calculator. The reaction 6 ClO2 + 2BrF3 -> 6ClO2F + Br2 is carried out with 12 mol ClO2 and 5 mol BrF3. (b) Estimate how many moles of each product will be produced and how many moles of the excess reactant will remain.

Chin_Alyssa_3I

Okay make sense. So with that in mind then for part b, since for 1 mol of Na2CO3 there is only 1 mol CO32-, you would just divide the mol with .08 M, correct?

Chin_Alyssa_3I

G.5 A student prepared a solution of sodium carbonate by adding 2.111 g of the solid to a 250.0-mL volumetric fl ask and adding water to the mark. Some of this solution was transferred to a buret. What volume of solution should the student transfer into a fl ask to obtain (a) 2.15 mmol Na+; (b) 4.98...

CHEMISTRY COMMUNITY

Search found 34 matches

Re: Winter 2016 Final Question 4 [ENDORSED]

Re: Saying Thank You to Dr. Lavelle

Question 15.65 Part B

Question on Actual Quiz 2

Re: Post All Chemistry Jokes Here

Re: 2/24/17 Bruincast

Re: Post All Chemistry Jokes Here

Re: Midterm Winter 2017

Possible course reader error?

Winter 2013 Midterm Q2A

Re: Enthalpy

Re: Review?

Ch 8.85

Kekulé structure?

Problem 8.65

Re: Post All Chemistry Jokes Here

Sig figs in calculations for pH and pOH

Problem 11. 87

11.73 b

Re: Naming Question and Coord. # for Nitrito

Naming Question and Coord. # for Nitrito

Re: Chem 14A Midterm Fall 2016 Rooms & Review Sessions

Re: Chem 14A Midterm Fall 2016 Rooms & Review Sessions

sp^2 Hybridization

Re: Chem 14A Midterm Fall 2016 Rooms & Review Sessions

Re: Post All Chemistry Jokes Here

Calculating EN Difference [ENDORSED]

Quiz 1 Fall 2015 #3 [ENDORSED]

1.15....Where did I go wrong? [ENDORSED]

Re: Atomic Spectra Post Assessment Question

Re: Fundamentals M.5 Part B

Fundamentals M.5 Part B

Re: Fundamentals G5

Fundamentals G5