Search: chem- electrochem-HELP

Number of results: 13,392

chem- electrochem-HELP
got my questions meixed up! I have tried this one by getting the 3 half-rxn and adding them up. then using E=E*-RT/nF InQ. i get close to an answer but not exact. i get 0.088V
Saturday, September 18, 2010 at 9:29pm by lucylu

chem- electrochem-HELP
I responded to this recently by saying you needed to clarify what these numbers are. I have no idea what they mean. That may explain why no one has answered you because no one can figure out to what these numbers refer.
Saturday, September 18, 2010 at 9:36pm by DrBob222

chemistry- electrochem
thanks DR BOB, i did get that. they have given us an assignment for distant ed. students and we haven't even covered the topic yet. the assignment is due the day we start the electro chem topic! not good. thankyou
Wednesday, September 15, 2010 at 4:06am by lucylu

chem- electrochem-HELP
Determine the equilibrium constant, Keq, for the reaction 5.3 10–19 18.30 1.7 1054 1.9 1018 5.7 10–55 i have tried this but get the wrong answer. i have the half-rxn and fugured out E=0.536. then used eq dG=-nFE, followed by dG=-RTInK. PLS HELP
Saturday, September 18, 2010 at 9:36pm by lucylu

chem- electrochem-HELP
thank you so much. I stuffed up at the start. i had 3 half-rxn. i didnt see that there was one for AgCl- it all makes thank. thankyou for your patience, It appriciated. I had to cram this subject in to get this assignment done. we are not supposed to start this topic til ...
Saturday, September 18, 2010 at 9:29pm by lucylu

Electrochem
I'm wondering the exact problem! I don't do how to write the balanced equation..
Sunday, May 13, 2007 at 3:58pm by India

Science
Thank you for using the Jiskha Homework Help Forum. Try the following; 1. (Wikipedia): http://en.wikipedia.org/wiki/Electrochemical_cell 2. http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/electrochem.html 3. http://library.kcc.hawaii.edu/external/chemistry/everyday_electro...
Wednesday, May 28, 2008 at 7:41pm by SraJMcGin

chemistry-electrochem
i need help. my assignmetn its due in less than 24 hrs. can anyone tell me where i went wrong?
Thursday, September 16, 2010 at 6:48am by lucylu

chemistry-electrochem
These numbers must refer to paragraphs, problems, chapters, or something of that nature where the full problem is found.
Thursday, September 16, 2010 at 6:48am by DrBpb222

chem- electrochem-HELP
right then, numbers are- Br2 + 2e- = 2Br E=1.065V I2(s)+ 2e- = 2I- E=0.536V i have placed both these numbers into eq- Ecell= Ered(cathode)-Ered(anode) but for every combination, using the before mentioned eq, i cannot get any answers that they offer. If E i get either +/- 1....
Saturday, September 18, 2010 at 9:36pm by lucylu

chem- electrochem-HELP
Given a cell based on the spontaneous reaction 2AgCl(s) + Zn(s) ® 2Ag(s) + 2Cl– + Zn2+ If the zinc ion concentration is kept constant at 1 M, and the chlorine ion concentration is decreased from 1 M to 0.001 M, the cell voltage should increase by 0.06 V increase by 0....
Saturday, September 18, 2010 at 9:29pm by lucylu

chemistry-electrochem
Determine the equilibrium constant, Keq, for the reaction 5.3 10–19 18.30 1.7 1054 1.9 1018 5.7 10–55 this is an assignment question- as writen, no values, nothing. any help
Thursday, September 16, 2010 at 6:48am by lucylu

chemistry- electrochem
Complete and balance the following redox equation. The sum of the coefficients when they are all whole numbers is MnO4- + H+ + Br-® Mn2+ + Br2 + H2O (acidic solution) 6 17 21 29 43
Friday, September 17, 2010 at 9:14am by lucylu

chemistry-electrochem
that is the full question. i cut and pasted it. i have emailed the lectures and have heard nothing...as usual. i have asked them if there should be more infor or a picture or something but nothing! how am i supposed to do it then?
Thursday, September 16, 2010 at 6:48am by lucylu

Chemistry/Electrochem
Consider a cell at 299K: line notation Fe-Fe2+(1.39)--Cd2+(2.35)-Cd Given the overall standard reduction potential of the cell is -0.038. What will the concentration of the Cd2+ solution be when the cell is dead?
Monday, October 1, 2012 at 2:27pm by Andres

chemistry- electrochem
just one thing on this dr bob, i thought that it was Ecell= E*cathode-E*anode. Why do you have a + sign between the 2. E1+E2? your way i get 0.35+(-0.13)=0.22, but my way i get 0.35-(-0.13)=0.48? which one?
Wednesday, September 15, 2010 at 4:06am by lucylu

chemistry- electrochem
equation 1 written as is = E1 for equation 2 reversed E for E2 = -0.13 E1 + E2 = 0.35 + (-0.13) = ??
Wednesday, September 15, 2010 at 4:06am by DrBob222

chemistry- electrochem
Mn in MnO4^- goes from +7 on the left to +2 on the right. Br goes from -2 (for 2 Br^-) on the left to 0 on the right (for two Br atoms). Now you balance.
Friday, September 17, 2010 at 9:14am by DrBob222

chemistry- electrochem
A cell can be prepared from copper and tin. What is the E° cellfor the cell that forms from the following half reactions? Cu2+(aq) + 2e-Cu(s) E° = 0.35 V Sn4+(aq) + 2e- Sn2+(aq) E° = 0.13 V a. 0.48 V b. 0.22 V c. -0.48 V d. -0.22 V
Wednesday, September 15, 2010 at 4:06am by lucylu

chemistry-electrochem
Dr BOB, i just spoke to my lecturer and he says to use reduction potentials and half equations + Ecall=Ered(cathode)+Ered(anode). so i get half equ: 2Br->Br2+2e- E=-1.065V I2(s)+2e- -> 2I- E=0.536V from this i get Ecell=-1.601V but i dont know where to go from ...
Thursday, September 16, 2010 at 6:48am by lucylu

Chemistry
What's the difference between a galvanic and electrolytic cell when trying to find which half-rxn is the anode or the cathode? So like when you have two equations, depending on what kind of cell it's in, how can you tell which one is the anode and which one is the ...
Tuesday, April 13, 2010 at 9:29pm by Nikki

AP Chem
I looked at the first four, they are right. Dont you work with someone on chem homework? Like a study group? That is a very effective way to work chem and physics problems.
Wednesday, November 19, 2008 at 11:22am by bobpursley

electrochem
Between Mg and Zn which one is the anode and which one is the cathode? And between Mg and Fe which one is the anode and which one is the cathode? Please and thank you. im so stuck. :/
Monday, April 8, 2013 at 11:02am by shyanne

Chemistry/Electrochem
A concentration cell is built based on the following half reaction: Zn(2+) + 2e(-) > Zn E(o)=-0.761 Using two pieces of zinc of electrodes (each 100.0 g), two Zn(2+) solutions, 0.101M and 0.427M (both exactly 1.00 L in volume), and all the other materials needed for a ...
Monday, October 1, 2012 at 2:32pm by Andres

chemistry- electrochem
Given a cell based on the spontaneous reaction 2AgCl(s) + Zn(s) ® 2Ag(s) + 2Cl– + Zn2+ If the zinc ion concentration is kept constant at 1 M, and the chlorine ion concentration is decreased from 1 M to 0.001 M, the cell voltage should increase by 0.06 V increase by 0....
Friday, September 17, 2010 at 9:15am by lucylu

chem- electrochem-HELP
Look up E* for Zn (as written). I find 0.763. Look up AgCl(s) + e ==> Ag(s) + Cl^- (as written). I find 0.222 Add to find E*cell. I find 0.985 Then Ecell = E*cell -(0.06/n)log(products/reactants). Ecell = E*-(0.06/n)log [(Zn^+2)(Ag)^2(Cl^-)^2/(Zn)(AgCl)] Now substitute ...
Saturday, September 18, 2010 at 9:29pm by DrBob222

Chemistry
please help! Is RTP in chemistry (thermochemistry and electrochemistry) referring to room temperature of 25degreeC (or 298K) and 1atm, or 20degreeC (293K) and 1atm? In my lecture notes on gas law, they stated RTP refers to 25degreeC, but in my electrochem lecture notes they ...
Sunday, November 6, 2011 at 4:57am by Hailey

chem help
ok thanks alot... the PartB asks for: What is the percent ionization of ammonia at this concentration?
Saturday, February 28, 2009 at 11:56pm by chem

chem
I DONT GET WHATS DONE.. DR.Bob22 - could u please explain this again..thank u
Tuesday, February 17, 2009 at 12:10am by CHEM

gen chem
i tried that, apparently its not the right answer either =/.
Saturday, May 8, 2010 at 7:46pm by Chem

CHEM organic chem
Responded above to a later repost.
Tuesday, November 13, 2007 at 6:18pm by DrBob222

Chem
0.102 x 0.0821 x 273 / 1.0 what can i express this in the correct number of significant figures ?@_@
Wednesday, August 29, 2012 at 4:51am by Chem ):

chem
... This isn't in the right section. That's math, not chem. the answer though is, 23.
Wednesday, February 10, 2010 at 7:40pm by Nadia Samim

O.CHEM -> PLEASE CHECK!!
Thank you...good to know, but isn't there a "Dr.Russ" that works with Organic Chem??
Wednesday, March 12, 2008 at 9:48pm by K

Chemistry, electrochem
(1) Half-reactions are written as ______ reactions with charge and mass balanced. (2) Among the ions, Cd^2+, Pb^2+ & Ca^2+, ________ has the greatest ability to reduce to its neutral metal. (3) Among the neutral metals; Pb, Ca & Cd, ________ has the least ability to ...
Sunday, May 11, 2008 at 6:08pm by Terry

G-chem/org. chem=>Dr. Bob222
I mean are setups differ for part 1
Friday, February 8, 2013 at 5:58pm by Devron

chem
The answer on mast chem is 279 if you have 230 grams instead of 200.
Monday, February 15, 2010 at 4:46pm by Anonymous

Chem
maybe try using P1V1/n1T1 = P2V2/n2T2 ... im in chem too...
Saturday, February 27, 2010 at 1:16am by fellow student

chem
sorry read it wrong, doing this now in chem
Tuesday, March 19, 2013 at 6:02pm by Amanda

chem
How to find the %(W/V) of 134mL of a 0.610 M solution of Mg(OH)2
Thursday, February 16, 2012 at 9:00pm by chem

organic chem
cadaverine is AKA pentane-1,5-diamine
Tuesday, April 26, 2011 at 5:18am by chem

gen chem
yes, I figured that one out. Thanks so much for the help!
Sunday, May 9, 2010 at 3:42pm by Chem

chem help
sorry the 2nd question is the right one
Saturday, February 28, 2009 at 11:56pm by chem

chem PLEASE HELP
I am very sorry. Chem is just not my thing and i looked in my notes the book and everything
Thursday, April 14, 2011 at 7:40pm by Sal

Chemistry/Electrochem
Consider a cell at 255 K: line notation Pb-Pb2+(1.27M)--Fe3+(2.29M)-Fe Given the standard reduction potentials calculate the cell potential after the reaction operated long enough for Fe3+ to have changed by 1.432M? I know that Fe3+ is the cathode which will decrease in ...
Monday, October 1, 2012 at 2:17pm by Andres

chem
ahh i hate chemisty, i'm kindof slow too and everything confuses me in chem.!! i feel the same way as you:)
Thursday, May 29, 2008 at 9:59pm by bethany

CHEM
FUUUUKKKK CHEM
Monday, November 5, 2007 at 10:14pm by ABU EL 3BED

chem
Sarah, 4.70 is what you get when you do the -log (Ka)
Monday, April 4, 2011 at 1:24am by chem

Chemistry
so the first one is wrong too hmmm ! yeah ur reasoning makes sense ... i will ask my chem teacher too
Saturday, November 28, 2009 at 8:14pm by Chem Lover

Chem
1. 7.95 g 2. 7.956 g 3. 7.96 g 4. 7.960 g 5. 8.0 g 6. 8.00 7. none of the above Which is more the right choice....It can't be 7,6,5 for sure....But I thought it was 3. It's not 2.
Friday, February 8, 2008 at 3:13pm by Chem Help!!

Science
These sites should get you started on your way to knowing everthing about this subject. http://volcano.und.edu/vwdocs/minerals/bauxite.html http://www.mii.org/Minerals/photoal.html http://www.elmhurst.edu/~chm/vchembook/327aluminum.html http://www.wmrc.uiuc.edu/info/...
Thursday, April 17, 2008 at 1:17pm by Ms. Sue

gen chem
what must be the current in amperes to plate out 7.437g of Al from am aqueous solution of Al3+ in 5.4x10^2 minutes?
Saturday, May 8, 2010 at 6:56pm by Chem

G-chem/org. chem=>Dr. Bob222
I just looked at Dr. Bob222's post for when you initially posted this question and the setup that I gave you for part 1 differs from the setup that he gave you for part 2. I will let him resolve that for you since he has more experience in G-chem then I do, and he is ...
Friday, February 8, 2013 at 5:58pm by Devron

gen chem
that works! thank you so much!!
Sunday, May 9, 2010 at 3:42pm by Chem

gen chem
yes, it wants an actual value
Sunday, May 9, 2010 at 3:17pm by Chem

gen chem
what is "n" and thank you so much for all the help!
Saturday, May 8, 2010 at 7:46pm by Chem

Chem
The correction terms in the Van der Waals equation for a gas are designed to correct A. the pressure term (P +a/V2) for the attractive forces between particles. B. the volume term (V-b) for the finite volume of the particles. C. For the volume term (b) not the pressure term (a...
Wednesday, October 18, 2006 at 7:23pm by Mendi

chem help
see the short paragraph and visual titled Predicting ion charges. http://antoine.frostburg.edu/chem/senese/101/atoms/
Saturday, November 24, 2007 at 7:59pm by bobpursley

gen chem
2NO <-> N2 O2 initial .116 0 0 change -x +x +x equil .116-x x x
Sunday, May 9, 2010 at 3:42pm by Chem

Intergated chemistry/physics
time=distance/velocity. This is a very odd question for "integerated" chem/physics. Where is the chem?
Wednesday, October 3, 2012 at 1:53pm by bobpursley

gen chem
yes I did, but im still not getting the right answer. I got .1136 which is not the correct answer.
Sunday, May 9, 2010 at 3:42pm by Chem

chem help
Ammonia,is a weak base with a Kb value of 1.8x10^-5 .What is the pH of a 0.22M ammonia solution?
Saturday, February 28, 2009 at 11:56pm by chem

chem help
Ammonia,is a weak base with a Ka value of 1.8x10^-5 .What is the pH of a 0.22M ammonia solution?
Saturday, February 28, 2009 at 11:56pm by chem

chem: study of kinetics
he gave us an example of what the slope might be in class and it was -1.3x10^2 but my slop is completely different, was i supposed to do calculations? or just get the one from excel? what do i put in the 2 blanks?
Saturday, October 16, 2010 at 2:20pm by chem

ap chemistry
I agree on the tutor. Also, get another text (college used book store) to see the same material in differing words. On the ap chem board exam, nationally, most do not do well. I have to be honest, most ap chem students need to retake college chem if for nothing else, the lab ...
Sunday, November 4, 2012 at 4:07pm by bobpursley

gen chem
what would Qc be if the pressure of the container decreased by a factor of 2.417 for the following reaction? 4Hcl(g)+O2(g)<-->2Cl2(g)+2H2O(g) Kc=13.298 @ 753K
Sunday, May 9, 2010 at 3:17pm by Chem

In your opinion=> has it payed off for you Dr.Bob? (I need some advice)
I don't know where to start but I was thinking of changing my major to chemistry but that would require me to go to another school since mine doesn't have a chemistry major. This is rather ironic since they have all the major chem classes needed to get a chemistry ...
Tuesday, March 25, 2008 at 9:50pm by ~christina~

chem
The larger an atom the farther the electrons are away from the nucleus; therefore, the easier it is to distort them. Here is a site that talks about that. http://www.chem.purdue.edu/gchelp/liquids/disperse.html
Friday, November 28, 2008 at 4:49pm by DrBob222

chem
You have to subtract the water vapor pressure at 25C from 760Torr. http://intro.chem.okstate.edu/1515sp01/database/vpwater.html
Tuesday, February 2, 2010 at 10:41pm by bobpursley

physics vs. Chem
Doesnt physics seem to be harder than chem? Anyone?
Sunday, October 24, 2010 at 2:28pm by Kavi

gen chem
E cell is not given, just the E0 cell which is -1.133V
Saturday, May 8, 2010 at 7:46pm by Chem

chem- drbob222 please help
my original question was: how do i figure this out?? How much heat does your body lose when 2.46 g of sweat evaporates from your skin at 25°C? chem - DrBob222, Tuesday, February 22, 2011 at 10:52pm q = mass water x delta Hvaporization. chem - Rebekah, Wednesday, February ...
Wednesday, February 23, 2011 at 5:49pm by Rebekah

Chemistry
I'm lost!!! Not sure if I'm just losing concentration after 50 chem problems or losing my mind with 3 kids running around still and a chem exam at 8am!!!
Friday, March 29, 2013 at 12:15am by Ryan Curry

Chem 2
Sorry my friend Barbie and I are doing are chem h.w. together. We each posted a question and since were using the same computer the last name always stays saved in the page...sorry I forgot to change it. It
Wednesday, February 27, 2008 at 3:28pm by Amanda

Chem
What causes dispersion forces? Disperson forces are caused by an unsymettrical distribution of charge in the molecule, causing a net electric force. http://www.chem.purdue.edu/gchelp/liquids/disperse.html
Tuesday, January 9, 2007 at 6:46am by Dennis

Chem Help!
I really need help with this question for my chem H.W. 1) On a summer day in Breckenridge, Colorado, the atmospheric pressure is 525 mm Hg. What is this air pressure in atmospheres? (round to the hundredths place) atm
Thursday, April 10, 2008 at 12:34pm by Lisa

HARD CHEM QUESTION- any help appreciated
Have you ever heard of ICE charts? http://www.chem.purdue.edu/gchelp/howtosolveit/Equilibrium/ICEchart.htm
Monday, May 13, 2013 at 8:48pm by bobpursley

chem:ionic equations
Here are a set of rules for solubility. Memorize them. http://www.chem.vt.edu/RVGS/ACT/notes/solubility_rules.html
Tuesday, November 27, 2007 at 12:15am by DrBob222

chem
Al is an element. The others are compounds. Consult this site for solubility. http://www.chem.vt.edu/RVGS/ACT/notes/solubility_rules.html
Monday, October 8, 2007 at 9:39pm by DrBob222

gen chem
what is the pK (=-logK)at 25C for the reaction below? Cl2(g)+6H2O(l)+5Cu2+(aq)<-->2ClO3-(aq)+12H+(aq)+5Cu(s) E0=-1.133V
Saturday, May 8, 2010 at 7:46pm by Chem

CHEMISTRY
AMMONIA GAS OCCUPIES A VOLUME OF 5.00 L AT 4DEGREES C AT 760 TORR. FIND ITS VOLUME AT77DEGREES C AND 800 TORR
Wednesday, July 7, 2010 at 10:44pm by CHEM CHEM

chemistry
http://dwb4.unl.edu/Chem/CHEM869J/CHEM869JLinks/www.chem.ualberta.ca/courses/plambeck/p101/p01182.htm
Monday, March 8, 2010 at 1:54am by DrBob222

Chem
Christina, Hello I'm Lisa. Thank you for your help you provided for my chem assignment. I really appreciate it! Have a nice day!
Tuesday, March 11, 2008 at 6:29pm by from Lisa to Christina

Dr.Bob222 Chem
I believe that you are correct because you have more experience in G-chem then I have. But how does doubling the reaction rate double the k value? Isn't k just a constant for a particular reaction?
Friday, February 1, 2013 at 10:15pm by Devron

College Chem 1010
Here is a simplified list of solubility rules. http://www.files.chem.vt.edu/RVGS/ACT/notes/solubility_rules.html A) Ca(NO3)2 B) FePO4 C) NH4OH D) Na2SO4 E) NaCl
Sunday, April 15, 2012 at 10:48pm by DrBob222

chem
if a car produces 81g of {\rm CO_2}, how many grams of {\rm O_2} are used up in the reaction? the complete chem reaction is C2H6O+3O2--->2CO2+3H2O
Friday, October 19, 2012 at 8:20am by tracy

gen chem
At 2273K, equilibrium constant for the reaction 2NO(g)<->N2(g)+O2(g) Kc=2.4x10^3 What would be equilibrim concentration of N2, if initial concentration of NO was 0.1160M?
Sunday, May 9, 2010 at 3:42pm by Chem

chem
so i posted this question yesturday and got some help. which is the stuff below. can you look at the last thing i said which was the answer i got by doing what DrBob222 said to do and tell me if its correct.(the question is the first section) thanks chem - hannah, A salt ...
Wednesday, November 10, 2010 at 4:18pm by hannah

Chem answer check
PbI2 is an insoluble salt. See the solubility rules. http://www.files.chem.vt.edu/RVGS/ACT/notes/solubility_rules.html
Monday, February 22, 2010 at 5:12pm by DrBob222

Chem
We are unable to draw diagrams on these boards. However, here is a site that gives the structure for #1 together with the resonance structures. If I find the structure on the web for #2 I shall post it. http://www.chem.ucsb.edu/~genchem/Chem1CS03/examanswers/final_white.pdf
Monday, September 7, 2009 at 12:07pm by DrBob222

college chem
http://www.chem.uiuc.edu/chem103/aluminum/AlIntroduction.htm
Tuesday, June 26, 2012 at 1:36am by bobpursley

Chem 1
Write a chemical equation that shows how acid rain H2SO3 was produced from SO2 gas and water in a zip sealed bag? My chem. teacher never explained how to do this and I have several other questions on this type of subject. If you could help me out it would help me tremendously...
Tuesday, April 9, 2013 at 8:00pm by Jess

Chem
You need to know the solubility rules. Here is a simplified set. http://www.files.chem.vt.edu/RVGS/ACT/notes/solubility_rules.html
Sunday, February 13, 2011 at 7:22pm by DrBob222

sand bath (chem)
what are disadvantages and advantages of using a sand bath to heat something in chem?
Sunday, October 21, 2007 at 7:31pm by ~christina~

Chem help
Here is a site that give you some insight on lattice energy. http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch7/lattice.html Yes, paramegnetic species will be those that have unpaired electrons. s and p.
Wednesday, November 28, 2007 at 1:01pm by DrBob222

chem
Here is a simplified set of solubility rules. http://www.files.chem.vt.edu/RVGS/ACT/notes/solubility_rules.html
Thursday, February 10, 2011 at 11:49pm by DrBob222

Chem
complete and balance the following decompition equations CaCO (heated) --> 3 please tell me how to do this and what exactly is suppose to be going through my head while doing this. I can balance these equations with no problem I just have no idea what to do...
Wednesday, December 17, 2008 at 7:09pm by Chem

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