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lwdandcasey Dasey King/Queen

Joined: 08 Nov 2007 Posts: 443
Location: Daseyland!
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Posted: Thu Apr 03, 2008 11:02 pm Post subject: High School Chemistry whizzes come forth! |
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Okay so does anyone know how to do these problems? If so please explain it to me in the best way possible, and I mean a thorough explanation.
Yes...I'm slow.
1. What is the concentration of 34.6 grams of NaCl dissolved in 4.59 liters of solution?
2. How many mols of solute are in 350 mls of a 0.0895 M solution?
3. 2AgNO3(aq) + MgCI2(aq) < > 2AgCL2(aq)
150 ML of 0.35 M MgCI2 should produce how many grams of AgCI? _________________
Artemus: Plush, Mr. Pudding.
If you can figure out where this is from I'll give you a cookie. ;) |
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dasey617 Dasey Shipper

Joined: 01 Dec 2007 Posts: 136
Location: New York
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Posted: Fri Apr 04, 2008 1:05 am Post subject: |
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Chemistry sucks. So, don't feel bad about not getting it.
This is what I think.
1) Concentration is refering to the molarity of the compound, and
Molarity= moles of solute / liters of solution
So, first you have to convert grams to moles of NaCl. There are 40 grams per mole, so 34.6 grams = 0.865 moles of NaCl.
Therefore, molarity= 0.865 moles/4.59 liters = 0.188453159. I'm not sure what you have to round it to.
2) This uses the same formula, so I'm not typing it again I'll just plug it in for you.
0.0895 M= X moles of solute/.35 liters of solution ((350mL/1000=0.35L))
*cross multiply*
0.0895 times 0.35 = 0.031325 moles of solute. Again, I'm not sure what to round to.
3) Again, same starting formula.
Plug in:
0.35M= X moles of solute/0.15 liters of solution ((mL->L))
*cross multiply
0.35 times 0.15 = 0.0525 moles of solute.
This number has to be converted to grams.
There are 143.4 grams of AgCl per mole.
So, to convert, you simply multiply:
0.0525 times 143.4 = 7.5285.
Again, you didn't specify rounding.
*** Hope I'm right and I hope this helps. I tried.  _________________
"Der-ek! What did you do to the kids?!"
*The forcefield is activated.* |
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lwdandcasey Dasey King/Queen

Joined: 08 Nov 2007 Posts: 443
Location: Daseyland!
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Posted: Fri Apr 04, 2008 2:30 pm Post subject: |
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Thanks! _________________
Artemus: Plush, Mr. Pudding.
If you can figure out where this is from I'll give you a cookie. ;) |
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dasey617 Dasey Shipper

Joined: 01 Dec 2007 Posts: 136
Location: New York
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Posted: Sat Apr 05, 2008 3:04 am Post subject: |
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No problem _________________
"Der-ek! What did you do to the kids?!"
*The forcefield is activated.* |
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