Question
I need to prepare standard solutions containing 1, 2, 3, 4.and 5 ppm Mn (= g Mn/mL). I will be taking an alreadyprepared solution containing 100 ppm Mn, and to prepare the 1-ppmstandard I will pipet 1.00ml of the already prepared solution intoa 100ml volumetric flask and dilute to 100ml with 0.05 MHNO3. Similarly, I will pipet 2.00, 3.00, 4.00, and 5.00 mlinto the other flasks and dilute each to 100ml with 0.05 MHNO3. How do I calculate the concentration of Mn ing/ml in each standard??? Thank-you much!! I need to prepare standard solutions containing 1, 2, 3, 4.and 5 ppm Mn (= g Mn/mL). I will be taking an alreadyprepared solution containing 100 ppm Mn, and to prepare the 1-ppmstandard I will pipet 1.00ml of the already prepared solution intoa 100ml volumetric flask and dilute to 100ml with 0.05 MHNO3. Similarly, I will pipet 2.00, 3.00, 4.00, and 5.00 mlinto the other flasks and dilute each to 100ml with 0.05 MHNO3. How do I calculate the concentration of Mn ing/ml in each standard??? Thank-you much!!
Explanation / Answer
If your already prepared solutions contains 100gMn/mL,which you told me, then calculate the concentration of the alreadyprepared solution (in g.mL) by 100g Mn / mLprepared solution Then you are diluting it with 0.05M HNO3, the factthat it is HNO3 does not effect the concentration of Mntherefore, you just useC1V1=C2V2 where C1 isthe concentration of the prepared solution, and V1 is the volume ofsolution added (for 1 V1 would be 1mL). V2 is the finalvolume, 100mL concentration C2=C1V1/V2