Question #f1ee8

1 Answer
Jan 1, 2015

I think you are dealing with a volume-to-volume percent concentration (v/v%), which is defined as the volume of the solute divided by the total volume of the solution and multiplied by 100%. This is mathematically described as

v/v%=volume of solutetotal volume of solution100%

So, in your case, you have a volume of solute equal to 50μL and a volume of solvent, NOT of total solution, equal to 200μL.

You add the solute to the solvent and get a total volume of solution of

50 μL+200 μL=250 μ L, which means that your v/v percent concentration is

v/v%=50μL250μL100%=20%

So, essentially, you have dilluted the original 50μL sample to 1/5th of its original concentration:

Cinitial50μL=Cfinal250μLCfinal=Cinitial50μL250μL

Cfinal=Cinitial5.