Question

You are presented with 10 millileters of a proteins solution that is at a concentration of 100 millimolars. You dilute the solution by taking 1 microliter of the solution putting it in an empty test tube then add adding 99 ul of buffer for your experiment. What is your final concentration of the peptide solution that is in this test tube.

*The answer key says that the answer is 10^-3 M*

If this is the answer can you please show work. Thank you.

Answer 1

Answer-

1. We have 10ml of protein solution with concentration 100mM. If we dilute the solution by taking 1l of solution and putting it in an empty test tube and then 99l of buffer is added then the final concentration of of the peptide solution in test tube is-

Dilution can be calculated by formula-

C1V1=C2V2

Where, C1= initial concentration of protein solution (100mM)

V1= volume taken from stock solution (1l)

C2= final concentration of protein solution

V2= volume of working solution in test tube (100l)

By putting these values-

C1V1=C2V2

100mM×1l=C2×100l

C2= 1×100/100

C2=1mM = 10^-3M( as 1M=1000mM)

  The final concentration of the peptide solution in test tube is 1mM i. e. 10^-3M.