CHEMISTRY COMMUNITY

Kira Conde 2O

Hello, I am attempting 2010 final question 4B and it honestly just seems so hard to me. There are buffers and PH involved, and though we learned those in 14A, they are really confusing me. The question reads: When a pH meter was standardized with boric acid-borate buffer with a pH of 9.40, the cell ...

Kira Conde 2O

Is this just for cycloalkanes? Why is it that I cannot call it dimethyl propane like the cross is usually called?

Kira Conde 2O

Hi, I'm having a problem naming the structure in this problem mostly because of the cross part. There is a section in the book that says the cross represents neopentane or 2,2 dimethyl propane... but in the book, the answer says it is tert butyl. I realize that tert is used for cycloalkanes, but is ...

Kira Conde 2O

Hi. I am still a bit confused on how to draw reaction mechanisms. If someone could help me understand this question that would be awesome. It reads: Draw the reaction mechanism for the reaction CH3Br+OH- --->(Equilibrium) CH3OH+ Br- Include the transition state, the geometry of the transition state ...

Kira Conde 2O

Hello, I was attempting to Bruincast yesterday's lecture and the Bruincast showed me a whole 50 minutes of a thermodynamics lecture when i went through and scanned it. I was confused because I know we are talking about Organic Chemistry in class now. Was there an error in updating it? If so, is it p...

Kira Conde 2O

Hi, I found this question in an old quiz prep book and I'm not sure how to do it. It reads: When 420 mg of NO2 is confined to a 150 ml reaction vessel and heated to 300 C it decomposes by a second order process with the rate of k= 0.54 l/mol/s. What is its initial rate? By what factor will the rate ...

Kira Conde 2O

Hi, I'm having a really hard time getting the value they specified for [Fe2+] for this problem. I get how we got from the Nerst Equation to 0.05916/2 log [Fe2+](0.015)^2/(0.015)^2 =2.05-2.20 but I'm not sure why you cant just simplify 0.05916/2 to 0.02958 instead of multiplying by two and then divid...

Kira Conde 2O

Hi guys, Electrochemistry still really confuses me and so I'm having a hard time answering this question. It reads: Using standard potentials given below, calculate the reaction quotient, Q, for the cell reaction given the cell emf =0V C(gr)|Cl2(g)|Cl-(aq)||Au3+(aq)|Au, E=0.00 V Au3+(aq)+3e--->Au(s)...

Kira Conde 2O

Hi, I am really confused as to how to get the answer to practice quiz question 11. I'm sure it's very simple, but I cant visualize what formula to use and its really hurting me. The problem is: How many grams of water can be heated from 25.0 degrees celsius to 110.0 degrees celsius by heat released ...

Kira Conde 2O

Hello,

I am having trouble calculating the entropy change in this problem.

Calculate the entropy change for: the freezing of 1 mol of h20 (l) at 0 degrees celsius (b.) the vaporization of 50 g off ethanol C2H5OH, at 351.5K.

Thanks in advance!

Kira Conde 2O

Hello, I understand bond enthalpies for the most part but question 75B is really confusing me. It asks "using the bond enthalpies from table 8.6 and 8.7 find the reaction enthalpy for CH3CHCH2+H20----->CH3CH(OH)CH3. I looked in the solution manual and it said that the bonds broken were only C-C...

Kira Conde 2O

Thank you both so much!

Kira Conde 2O

Hello, I am having a hard time with Hess's Law when I am not given both of the equations. The question that I am confused on is as follows: Determine the reaction enthalpy for C2H2+2H2---->C2H6 from the following data: Delta h sub c (C2H2,g)=-1300kJ.mol. Delta h sub c(C2H6,g)=-1560kJ.mol, and delta ...

Kira Conde 2O

The 2008 Midterm Question 8A states that we have amphetamine (C6H5CH2CH(CH3)NH2 with a pkb of 3.11. When it is ingested it makes the stomach a pH of 1.7 will it remain C6H5CH2CH(CH3)NH3+ OR will it be converted to C6H5CH2CH(CH3)NH2? That is what is the ratio of concentrations of the two species at t...

Kira Conde 2O

Hi, I'm having a hard time solving this problem because of the dilutions. It reads: A student added solid Na2O to a 200 ml flask which was filled with water, resulting in a 200 ml NaOH solution. 5.00 ml was then transferred and diluted to 500 ml. The pH of the diluted solution is 13.25. What is the ...

Kira Conde 2O

Hi, I am very confused as to how to answer this problem: Consider the following reaction: NH4HS=NH3+H2S If the value of Kp is 0.11 at 300K, calculate the equilibrium partial pressure of NH3 starting from pure NH4HS. Ive gotten as far as setting up the equilibrium constant expression(without the soli...

Kira Conde 2O

Hi, I am still having hard time naming the coordination compounds. Can you help me out with the [Fe(CN)6]4- and [Co(NH3)6]3+? I know that there is formula for finding the oxidation number of metals but I'm not sure if we've gone over it in class or how to use it. I also know that NH3 is ammine and C...

Kira Conde 2O

Hello, I understand the concept of polarity, but I'm a bit confused about how you find out the dipole moments. So, the question is "predict whether each of the following molecules will be polar" a. C5H5N b. C2H6 c. CHCl3 I believe that c is polar because not all of the molecules attached t...

Kira Conde 2O

Is a double bond between the same element stronger than a triple bond between two separate elements? I know that a triple bond is usually stronger, but I don't know if that is just for the same element. The example that I had a problem with a double bonded O atom and a C triple bonded to a N. Which ...

Kira Conde 2O

Hi, I am honestly so confused by the principal and orbital angular momentum quantum numbers for 6p, 3D, 2p, and 5f. I thought that it was like 2px,y, and z, or something like that, but the answer key says that it is n=6 l=1. I get why n=6, but i don't know why l=1. Isn't l 5,4,3,2, and one like when...

Kira Conde 2O

I was wondering if we can use the Bohr frequency condition as the Rydberg formula, In class, Professor Lavelle said something to this effect, and I was wondering if we could avoid the Rydberg formula. I tried to do 13 with the Bohr equation and it didn't work. Please help!

Kira Conde 2O

Hi guys. I'm doing problem 1.65 in the textbook and I thought it was a photoelectric problem, but I cannot figure it out for the life of me. I was trying to do it using wavelength=hc/e but I couldn't figure it out It states: The energy needed to break a C-C bond is 348 kj.mol will visible light be a...

Kira Conde 2O

THANK YOU SO MUCH!

Kira Conde 2O

Hello Everyone, I have been trying to get through the homework but I am having a dilemma with number 59 of chapter 1. The question reads: Each second a certain lamp produces 9.8*10^20 photons with a wavelength of 434 nm. How much energy is produced as radiation at this wavelength. I tried doing it a...

CHEMISTRY COMMUNITY

Search found 24 matches

2010 Final Question 4B

Re: 1.17 in the organic textbook

1.17 in the organic textbook

Question 4.34 in the Organic Textbook

2/24/17 Bruincast

Quiz Prep Question

2013 Midterm 8B

2007 Midterm Question 7

Quiz 1 Question 11

Homework Question 15

Bond Enthalpies Question 75 B

Re: Chapter 8 Homework Hess's Law #57

Chapter 8 Homework Hess's Law #57

2008 Midterm Question 8A [ENDORSED]

Number 33 in the Chapter 12 HW

Fall 2014 Quiz Prep #8

Number 29 from the Hw [ENDORSED]

Chapter 4 Number 27

Bond Lengths

Chapter 2 Problem 21

Can Bohr be used as Rydberg?

C-C bond breakage by visible light? [ENDORSED]

Re: Help with Question 59 in Chapter 1

Help with Question 59 in Chapter 1