Dilution question

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flatrpo
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Dilution question

Post by flatrpo » Wed May 12, 2010 10:45 am

Hey,

I have a solution of 18 wt % (about 1g/ml) I want to make it into a solution of 2 wt % by diluting it with water. Using C1 V1 = C2 V2 could someone show me how to do it. I have tried but seem to be getting muddled somewhere.

Thanks!

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JackBean
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Post by JackBean » Wed May 12, 2010 1:39 pm

what you used is for concentration on mol/dm3, not for wt %.

You have to use w1*m1 = w2*m2
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.

clevermizo
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Re: Dilution question

Post by clevermizo » Thu May 13, 2010 7:54 pm

The units are arbitrary at this point and don't affect the calculation, since the starting units and the ending units are the same.

If I have a solution of 18 fiddledeecups and I want to dilute it down to 2 fiddledeecups, well that's a dilution factor of 18/2 = 9.

So, if I want 9 mL, I use 1 mL of 18 fiddledeecups and add 8 mL of diluent (water in this case). Since the dilution factor is 9, make your final volume a multiple of 9 to make your calculations easier.

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JackBean
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Post by JackBean » Fri May 14, 2010 7:06 am

well, it does matter. If you had e.g. 96% H2SO4, whose density is about 1.4 g/ml, you cannot just dilute it twice to get 48% :roll:
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.

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