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get final concentration

Tue Jul 18, 2006 3:03 am

I need to make a solution that contains PAH (paraaminohippuric acid) at 25mmol/liter.
is this procedure right?
1. 25mmol/l divide by 1000=0.025mol/l
2. 0.025 mol/l x the MW of PAH which is 194.19g/mol =4.85475
does this mean i need to dissolve 4.85475 g of PAH in one liter to get the 25mmol/liter? What if the source of PAH is 99% or lower?
thanks in advance

nor

Re: get final concentration

Tue Jul 18, 2006 6:57 pm

NOR wrote:I need to make a solution that contains PAH (paraaminohippuric acid) at 25mmol/liter.
is this procedure right?
1. 25mmol/l divide by 1000=0.025mol/l
2. 0.025 mol/l x the MW of PAH which is 194.19g/mol =4.85475
does this mean i need to dissolve 4.85475 g of PAH in one liter to get the 25mmol/liter?


Yes. You will need about one liter of water, but volume may not be perfectly additive. Add water until you have 1 L of solution.

What if the source of PAH is 99% or lower?
thanks in advance
nor


Express the percentage as a decimal fraction (0.99). Divide the grams above by the purity fraction.

thanks a lot

Tue Jul 18, 2006 10:30 pm

Thank you very much!!!

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