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for the test (ch 6)
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Ch. 6 Energy
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Tuesday, 11:44 PM EST by
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Thread started: Tuesday, 11:44 PM EST
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do we have to know w= -P x change in V for the test tomorrow?
it was in the book, but we didnt really talk about it in class...
And is the answer key online for the one worksheet with 3 parts?
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AP Chem Failures/FMLs
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AP Chemistry 09-10
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Tuesday, 10:38 PM EST by
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Thread started: Sep 28 2009, 11:21 PM EDT
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Yes, we're supposed to be the best of the best, but sometimes, even AP students make mistakes.
This is just a spinoff of fmylife.com, but AP chemistry related! because let's face it, sometimes AP life sucks.
example:
Today, I spent twenty minutes navigating my AP chemistry website and trying to figure out how to post a comment to earn my five extra credit points. I was getting really confused so i was about to give up when I realized that I wasn't even signed in. FML.
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Last Reply:
RE: AP Chem Failures/FMLs
By: ,
Tuesday, 10:38 PM EST
Chem test and bio lab practical all in one day...tomorrow...back to back testing for three periods...fml
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How do you do number 83 in the book?
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Ch. 6 Energy
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Tuesday, 9:00 PM EST by
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Thread started: Tuesday, 7:53 PM EST
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I really just don't know how to go about solving it. For example, how do you get rid of the two moles of B2O3 when that chemical compound doesn't show up anywhere else in the equaitons?
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Last Reply:
RE: How do you do number 83 in the book?
By: ,
Tuesday, 9:00 PM EST
There is a B2O3 in the third equation. I would multiply that equation by (-2) so u get the 2B2O3 and you get it on the other side. There is also a typo and the first compound should be B2H6
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QUESTIONNNN~
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Discussion Forum
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Tuesday, 8:54 PM EST by
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Thread started: Tuesday, 8:47 PM EST
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when do you have to have to convert celcius into kelvins.. and vice versa.. and when do you not have to?
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Last Reply:
RE: QUESTIONNNN~
By: ,
Tuesday, 8:54 PM EST
Well I think you should just convert to match the units of the other units (so they cancel out), but when you are looking at change in temperature, its fine to leave it as it is because the conversion is just adding or subtracting by a constant and when you calculate change in temperature these cancel out.
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Chemistry Chuckles
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AP Chemistry 08-09
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Monday, 9:34 PM EST by
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Thread started: Sep 21 2008, 11:46 PM EDT
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Outside his buckyball home, one molecule overheard another molecule saying, "I'm positive that a free electron once stripped me of an electron after he lepton me. You gotta keep your ion them."
KC couldn't resist interjecting a little philosophy into a class lecture. He interrupted his discussion on balancing chemical equations, saying, "Remember, if you're not part of the solution, you're part of the precipitate!"
One day , while watching the Tonight Show, KC saw a classified add that read: "Do you have mole problems? If so, call Avogadro at 602-1023."
Q: What do chemists call a benzene ring with iron atoms replacing the carbon atoms?
A: A ferrous wheel:
Fe - Fe
/ \
Fe Fe
\ /
Fe - Fe
The Official Unabashed Scientific Dictionary defines cation as a positively charged kitten…meow.
Q: What is the name of the molecule bunny-O-bunny?
A: An ether bunny
Q: What is the chemical symbol for diarrhea?
A: (CO(NH2)2)2 ……… get it? Urea = CO(NH2)2.
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What did you already cover in this chapter?
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Ch. 6 Energy
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Nov 1 2009, 10:07 PM EST by
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Thread started: Oct 29 2009, 9:13 AM EDT
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What do you remember from Physics and Chem from before in energy? What are good connections in Bio as well?
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RE: What did you already cover in this chapter?
By: ,
Nov 1 2009, 10:07 PM EST
We learned about mc delta t and all of the change of state expressions (fusion and vaporization) We did not cover the heats of formation or reaction ever before. In physics we learned about internal energy changes and P-V graphs.
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You know you're a AP Chem student when...
(page: 1 2)
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Classroom
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21 |
Oct 21 2009, 10:59 PM EDT by
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Thread started: Sep 10 2009, 7:42 PM EDT
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I thought I would start a 09-10 version for all of us that want easy points or to share when you knew you were a AP chem student
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Question #6 on Chapter 4 AP Multiple Choice Problems
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Assignments
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Sep 28 2009, 11:41 PM EDT by
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Thread started: Sep 28 2009, 10:22 PM EDT
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Can any one explain how to get the answer to question 6 in the ch. 4 multiple choice ws?
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RE: Question #6 on Chapter 4 AP Multiple Choice Problems
By: ,
Sep 28 2009, 11:41 PM EDT
I think i explained number 12 in a different thread. For number 6 the only answer that divides evenly into all of the values is 19. If you think about the formula for a compound the number of moles of each element should be a whole number. So you should multiply the average atomic mass by a whole number. None of the other choices divide evenly into all of the numbers. The question is just saying that the mass of Q in different compounds has this much mass so first the first it would be Q(2) because 19 times 2 equals 38. The second would be Q(3) 19*3=57 and so on.
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Rollerer |
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How to do #12 and #14 in the Chapter 4 AP Multiple Choice Packet?
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Ch. 4 Stoichiometry and Basic Equations
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Sep 28 2009, 11:32 PM EDT by
Jerrycom42 |
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Thread started: Sep 28 2009, 11:16 PM EDT
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For number 12, do the 0 degrees C and 1.00 atm even matter? For number 14, do you just find the moles of Carbon from the .38 grams of CO2 formed and use percent weights of each element in the CaCO3 compound to find out how much the CaCO3 weighs alone or am I totally off?
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Chapter 4 Multiple Choice Problems # 5
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Discussion Forum
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Sep 28 2009, 11:10 PM EDT by
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Thread started: Sep 28 2009, 10:57 PM EDT
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Can someone just explain how to do #5 for me?
thanks!~
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RE: Chapter 4 Multiple Choice Problems # 5
By: ,
Sep 28 2009, 11:10 PM EDT
start with 24g O X 1 mol O / 16g O X 1 mol Ca(NO3)2 / 6 mol O X 164.0914g Ca(NO3)2 / 1 mol Ca(NO3)2=41g
so in words 24g O multiplied by 1mol O over 16g O, multiplied by 1 mol Ca(NO3)2 over 6 mol O, multiplied by 164.0914g Ca(NO3)2 over 1 mol Ca(NO3)2
that is the stoich. equation I set up is that good? If you are still confused I can explain more.
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excercise 4L.9
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Discussion Forum
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Sep 28 2009, 10:59 PM EDT by
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Thread started: Sep 28 2009, 10:59 PM EDT
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can anyone help me with this problem? It's in the study guide. <Phenylfluoroform contains 57.54% carbon, 3.45% hydrogen, and 39.01% fluorine. Its simplest formula is the same as its molecular formula. The number of carbon atoms in a molecule would be...> If anyone could get back to me it would help A LOT.
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Question #12 on Chapter 4 AP Multiple Choice Problems
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Assignments
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Sep 28 2009, 10:23 PM EDT by
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Thread started: Sep 28 2009, 10:23 PM EDT
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Can any one explain how to get the answer to question 12 in the ch. 4 multiple choice ws?
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Question #2 on Chapter 4 AP Multiple Choice Problems
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Assignments
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Sep 28 2009, 9:50 PM EDT by
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Thread started: Sep 28 2009, 7:43 PM EDT
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Can any one explain how to get the answer to question 2 in the ch. 4 multiple choice ws?
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RE: Question #2 on Chapter 4 AP Multiple Choice Problems
By: ,
Sep 28 2009, 9:50 PM EDT
First, I balanced the equation and had 2CnH2n + 302 yields CO2 + 2H2O. (the n's and numbers after elements are subscripts) Then i solved for the molar mass of CH2. Since we have n as a subscript for both C and H, it is possible to look at is as n(CH2). If we use different n's and balance the equations and solve for # of moles of H20 formed starting with .561 g CnH2n we get around .04 moles everytime.
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What did you use to learn the Ions?
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Intro Materials Ch. 1-3
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10 |
Sep 13 2009, 9:00 PM EDT by
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Thread started: Sep 7 2009, 12:58 PM EDT
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What helped you learn the ions for formula writing? Flash cards? Memorization tricks?
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AP Chemistry moments: You know that you are an AP Chem student when...
(page: 1 2 3)
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AP Chemistry 08-09
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54 |
May 4 2009, 9:13 AM EDT by
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Thread started: Aug 29 2008, 6:21 PM EDT
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Craddock wanted somebody to start the thread that included moments when u knew you were an AP Chem student...
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adding on
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Acid/Base Equilibrium
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1 |
Apr 2 2009, 12:16 AM EDT by
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Thread started: Apr 1 2009, 10:47 PM EDT
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pKw =14 = pH+ pOH
Ka= acid in water . K>1 strong acid and base K< 1 weak acid and base
Ka x Kb = Kw
one question is what are some of the basic strong acids and conjugate bases that we have to know Which ones are the general strong ones like .... and which ones are some of the ones we don't have to know as in aren't really important.
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Last Reply:
RE: adding on and question
By: ,
Apr 2 2009, 12:16 AM EDT
i think the general strong acids we need to know are like:
hydrochloric, hydrobromic, hydroiodic, nitric, perchloric, and sulfuric
weak acids:
phosphoric, carbonic, acetic
strong bases:
lithium hydroxide, sodium hydroxide, and potassium hydroxide
weak bases:
ammonia
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Confused?
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Chemical Kinetics
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4 |
Mar 15 2009, 11:42 PM EDT by
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Thread started: Mar 4 2009, 5:59 PM EST
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What do you need more help on or explanation on?
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Last Reply:
RE: Confused?
By: ,
Mar 15 2009, 11:42 PM EDT
"can you explain #8 on the chemical kinetics multiple choice questions? or I guess my question is why is B (and A) false? it says the answer is D.
(i'll type the question to make it easier...)
8. Which statement is true?
A. there is a single rate-determining step in any reaction mechanism
B. endothermic reactions have higher activation energies than exothermic reactions
C. the rate of a catalyzed reaction is independent of the concentration of the catalyst
D. the specific rate constant for a reaction is independent of the concentration of the reacting species
E. the rate law for a reaction depends on the concentrations of all reactants that appear in the stoichiometric equation
thanks!" Well first of all D is true due to the fact that k is a constant for that experiment at that temp, regardless of what the concentrations are. It is a constant, and that is when it is constant. A is false due to that it maybe saying that the rate determining step is the only step. In addition, it is possible to have more than one, we have just seen one in the examples. B is false (toughy) because that is not necessarily true. If they are simiar reactions, then yes. But some endo thermic reactions can have a small Ea and some exos can have a large Ea. Typically that is not the case, but not always. Good luck!
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2nd Semester
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AP Chemistry 08-09
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Jan 14 2009, 10:56 AM EST by
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Thread started: Jan 14 2009, 10:56 AM EST
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What do you want to make sure we do for your 2nd semester of Senior year? What have you always wanted to do in science class but have not? What would you like to repeat? Discuss!
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Book Codes
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Discussion Forum
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Jan 13 2009, 9:43 PM EST by
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Thread started: Jan 13 2009, 9:43 PM EST
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UMMMM... I kind of lost the online code for my book. Does anyone have one?
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Final Exams
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AP Chemistry 08-09
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2 |
Jan 8 2009, 2:11 PM EST by
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Thread started: Dec 30 2008, 5:08 PM EST
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What topic do you feel like you need to brush up on the most for finals? What kind of AP multiple choice questions do you always get wrong? Discuss!
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Last Reply:
RE: Final Exams
By: ,
Jan 8 2009, 2:11 PM EST
ions .... they are always different...
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