27-02-2004, 20:57
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#1
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Chemistry question :)
Didn't know where to put this so feel free to move it 
Here's something to frazzle your brains
You are provided with a solution containing 50ppm chloride ions. How many mls of this should be taken and diluted to produce 100ml of a 2.5ppm solution?
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27-02-2004, 21:08
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#2
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Re: Chemistry question :)
5 ml ?
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27-02-2004, 21:08
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#3
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Re: Chemistry question :)
 The only mark I got in my chemistry exam was for spelling my name correctly so don't be looking to me 
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27-02-2004, 21:12
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#4
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Re: Chemistry question :)
ummmm (swigs a beer)
TAKE 100 ml of the solution, dilute in half, then throw half away ??
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27-02-2004, 21:24
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#5
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Re: Chemistry question :)
20mls  wtf do I know???
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27-02-2004, 21:38
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#6
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Re: Chemistry question :)
Quote:
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Originally Posted by Xaccers
Didn't know where to put this so feel free to move it
Here's something to frazzle your brains
You are provided with a solution containing 50ppm chloride ions. How many mls of this should be taken and diluted to produce 100ml of a 2.5ppm solution? |
I'd say 20 ml
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27-02-2004, 21:41
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#7
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Re: Chemistry question :)
Quote:
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Originally Posted by pem
5 ml ?
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How did you come to that conclusion?
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27-02-2004, 21:43
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#8
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Re: Chemistry question :)
You didn't tell us what volume of the original solution we had 
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27-02-2004, 21:46
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#9
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Re: Chemistry question :)
Gut feeling is with pem, 5 mils, but something tells me it might be 5.263 or 4.762, but I haven't quite figured it out yet (ie, I may well be wrong).
To Ramrod, I think that may drop out of the equation...
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27-02-2004, 21:47
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#10
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Re: Chemistry question :)
Quote:
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Originally Posted by timewarrior2001
I'd say 20 ml
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How did you come to that conclusion?
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27-02-2004, 21:48
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#11
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Re: Chemistry question :)
Quote:
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Originally Posted by Ramrod
You didn't tell us what volume of the original solution we had |
Doesn't matter, taking 10ml for instance, out of 100ltrs of 50ppm solution will still contain the same number of ions as taking 10ml out fo 100000ltrs of a 50ppm solution
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27-02-2004, 21:50
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#12
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Re: Chemistry question :)
We are assuming that both the original solution and the dilutant have an equal number of molecules per mil aren't we?
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27-02-2004, 21:55
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#13
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Re: Chemistry question :)
Quote:
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Originally Posted by Xaccers
Doesn't matter, taking 10ml for instance, out of 100ltrs of 50ppm solution will still contain the same number of ions as taking 10ml out fo 100000ltrs of a 50ppm solution |
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27-02-2004, 21:56
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#14
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Re: Chemistry question :)
Right, I will try an explanation for the 5 mil answer then. Assuming 1 million parts per mililiter, you need add add 19 mils of solution (going by my above assumption) to get to 2.5 ppm. This makes 20, so multiply both by 5 to get to 100 total. So, 5 mils of the original
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27-02-2004, 22:00
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#15
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Re: Chemistry question :)
Quote:
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Originally Posted by danielf
Right, I will try an explanation for the 5 mil answer then. Assuming 1 million parts per mililiter, you need add add 19 mils of solution (going by my above assumption) to get to 2.5 ppm. This makes 20, so multiply both by 5 to get to 100 total. So, 5 mils of the original
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I concur
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