J.R. S. answered • 11/08/17

Tutor

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Ph.D. in Biochemistry--University Professor--Chemistry Tutor

There are several ways this can be done. Here is the simplest.

Calculate the OVERALL dilution factor:

25 ml to 100 ml = 4 fold dilution (100/25)

15 ml to 300 ml = 20 fold dilution (300/15)

Overall dilution factor = 4 x 20 = 80 fold dilution

Final concentration starting with 1.0 g/dl and applying an 80 fold dilution factor = 1/80 = 0.0125 g/dl

0.0125 g/dl x 1000 mg/g =

**12.5 mg/dl**Doing it by a more extended procedure (and there are many ways to do this as well):

1g/dl = 1 g/100 ml = 1000mg/100 ml = 10 mg/ml STOCK solution

First dilution: 10mg/ml x 25 ml = 250 mg put into 100 mls = 250 mg/100 ml

Second dilution: 250 mg/100 ml x 15 ml = 37.5 mg put into 300 ml = 37.5 mg/300 ml FINAL SOLUTION

Convert this to desired units of mg/dl: 37.5 mg/300 ml = 0.125 mg/ml; 0.125 mg/ml x 100 ml/dl =

**12.5 mg/dl**