hey
October 11, 2008, 07:00:02 PM
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1
on: Today at 06:55:45 PM
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| Started by amiv4 - Last post by amiv4 | ||
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so would it be 24.8% Cl-
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2
on: Today at 05:40:55 PM
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| Started by Zell - Last post by Zell | ||
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Hey everyone! I'm having trouble with the following question:
Tell whether it is possible to make a 1.0 M solution at 0 degrees C? a) CuSO4 x 5H2O, solubility = 23.1g/100mL b) AgNO3, solubility 122g/100mL I don't know how to begin or work through this problem. Thanks in advance!  |
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3
on: Today at 05:34:16 PM
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| Started by Chemistry Tutor - Last post by Zell | ||
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I searched for "chemistry help" on Google.
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4
on: Today at 03:51:50 PM
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| Started by roseybabyy - Last post by roseybabyy | ||
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This question is from the synthesis of alum lab.
"Why should you not wash the crystals with pure water?" Thanks! |
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5
on: Today at 03:24:08 PM
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| Started by tesfaw - Last post by tesfaw | ||
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Do copper and a hydrogen ion create a reaction?
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6
on: Today at 01:53:14 PM
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| Started by SchoolBoyDJ - Last post by SchoolBoyDJ | ||
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Second organic test this cominig monday
 1. Which of the following is not an electrophile? a) AlCl4-[/sub] b) BH3 c) NH4+ I was able to eliminate c, but the other two gave me trouble. My thinking was that: If carbon can form 4 bonds (sp3 hybridized), why can't Boron? So I was thinking Boron had an open p orbital (currently sp2 hybridized). AlCl4- seemed to already be full. I know that elements in period 3 or higher can form more than the expected number of bonds, but why the heck would something with full orbitals, and a negative charge still want more negative/electrons  2. The following is a ______ alkene  a)monosubstituted b)disubstituted c)trisubstituted d)tertasubstituted Now you'd name this 2-ethyl-1-butene right? I thought this would be monosubstituted because it has one group coming off the main chain. I guess substitution takes into account all R groups (everything but H right?) coming off the double bond? 3. When 2-pentene is heated with a catalytic amount of I2, an equilibrium concentration of two isomers is obtained. The dominant isomer is: c) an equal amount of each is present at equilibrium  I didn't have much of a guess on this, and I guess that's because I don't know what is happening to the molecule while reacting with I2. A is the correct answer, but with the knowledge I have now I'd argue b as it seems like it would be more stable...the pi bond almost seems more enclosed. Help >_< Thanks everyone! |
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7
on: Today at 11:31:22 AM
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| Started by harley08 - Last post by harley08 | ||
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Thank you, but believe it or not there was about 2 sentences and then it cuts off like a misprint. Unfortunately our teacher doesn't use the book to instruct from, she uses overhead projection and speeds thru those like a tornado, which can be frustrating. It is more of a teach yourself class. Anyway, THANK YOU, for both the help and letting me vent there.
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8
on: Today at 08:24:20 AM
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| Started by harley08 - Last post by Otis | ||
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In one mole of your compound you have 1 mole of Al3+ and 3 moles of Br-, that's what the subscripts mean. Now use your PT (Periodic Table of the Elements) to find the mass of one mole of the element.
For Al3+, 26.98 grams Al3+/1 mole Al3+ times 1 mole of Al3+ equals 26.98 grams Al3+ For Br-, 79.90 grams Br-/1 mole Br- times 3 moles Br- equals 239.70 grams Br- This should have been explained in you chem book with several examples. Otis |
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9
on: Today at 08:15:24 AM
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| Started by harley08 - Last post by harley08 | ||
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I have a question I am completely stumped on, we did not go over this in class and I can't find any type of problem like in in our books and I am the type that has to see how and why I am getting there in anything.
The question is; Calculate the mass in grams of positive and negative ions contained in one mol of AlBr3? Any help would be so much appreciated, as well as any sites that I could go to to help with chemistry in general, but of course the above question is pressing right now as I am stressed as to how to do it. |
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10
on: Today at 08:05:03 AM
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| Started by cyborg22 - Last post by Otis | ||
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Assign oxidation number following the rules in your chem book. Most important but often neglected - use the rules in the order given. Do not play hop-scotch with the rules.
1. All atoms in their elemental state are assigned zero 2. Group 1 and 2 and other simple ions are assigned their normal charge 3. Hydrogen is assigned 1+, except hydride is assigned 1- 4. Oxygen is assigned 2-, except peroxide is assigned 1- 5. The sum of the oxidation numbers must equal the net charge on the polyatomic ion or compound. Good luck, Otis Added To balance the redox equation see my reply (#9) at http://www.mychemistrytutor.com/forums/ap-chemistry/balancing-oxidation-reduction-equations/ |
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hey