The concentration of an unknown must be in the range of the known concentrations

Question

The concentration of an unknown must be in the range of the known concentrations. You sometimes must dilute an unknown so that the concentration is lower than thehighest concentration measured for your standard curve.

a. If you dilute 1mL of an unknown solution with 1 mL of water, the dilutedconcentration would be 1mL in a total of 2mL of solution. How would this affect the concentration? What is the dilution factor?

b. One would then have to reverse this process when reporting the original concentrationof the unknown solution. What factor would be used to calculate the originalconcentration?

c. If 1mL of unknown solution was diluted to 10mL final volume, what is the dilutionfactor? How would one calculate the original concentration?

d. If 2 mL of unknown solution was diluted to 5mL final volume, what is the dilutionfactor? How would one calculate the original concentration?

Explanation / Answer

a) When a solution's concentration is reduced, it is called dilution. Dilution factor is the total amount of solution per aliquot volume. It is the ratio of the final volume to the initial volume.

if you dilute 1 ml of an unknown solution with 1 ml of water then the concentration of the unknown solution will be half of its initial concentration.

dilution factor = final volume / initial volume = 2/1=2

b) you have to multiply 2 to get the original concentration.

c)if 1ml of unknown solution was diluted to 10 ml final volume then the dilution factor will be 10/1=10

to get the original concentration you have to multiply the dilution factor to the concentration which you will get after dilution.in this case you have to multiply 10 with the resultant concentration to get the original concentration.

d))if 2ml of unknown solution was diluted to 5 ml final volume then the dilution factor will be 5/2=2.5

to get the original concentration you have to multiply the dilution factor to the concentration which you will get after dilution.in this case you have to multiply 2.5 with the resultant concentration to get the original concentration.

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