1. You have a stock 0.100 M solution of
KMnO4 and a series of 100-mL volumetric
flasks. What volumes of the stock solution
will you have to pipet into the flasks to
prepare standards of 1.00, 2.00, 5.00, and
10.0 × 10−3 M KMnO4 solutio
Surely you have not typed the problem correctly. You can't get a 1.00 M solution starting with 0.1 M KMnO4. Surely you mean you want 1.00E-3, 2.00E-3, 3.00E-3 etc/
Into the first one pipet 1.00 mL, 2.00 mL into the second. 5.00 mL into the third, 10.00 mL into the last one. Make to the mark on the flask. Calculate the first one.
Thats 1.00 mL x 0.1 M = 100 mL x ?M
?M = 1.00 x 0.1 M/100 = 0.001 M
For the last one that is
10 mL x 0.1 M = 100 mL x ?M
?M = 0.1 M x 10/100 = 0.001 x 10 = 0.01M
To determine the volumes of the stock solution you need to pipet into the 100-mL volumetric flasks, you can use the formula for dilution:
C1V1 = C2V2
Where:
C1 = initial concentration of the stock solution
V1 = volume of the stock solution you will be using
C2 = final concentration of the diluted solution
V2 = final volume of the diluted solution (in this case, 100 mL)
Let's calculate the volumes of the stock solution for each desired concentration:
For 1.00 M:
C1 = 0.100 M
V1 = ?
C2 = 1.00 M
V2 = 100 mL
Using the formula:
0.100 M x V1 = 1.00 M x 100 mL
V1 = (1.00 M x 100 mL) / 0.100 M
V1 = 1000 mL
So, you will need to pipet 1000 mL (or 1.00 L) of the stock solution into the 100-mL volumetric flask to prepare a 1.00 M KMnO4 solution.
For 2.00 M:
C1 = 0.100 M
V1 = ?
C2 = 2.00 M
V2 = 100 mL
Using the formula:
0.100 M x V1 = 2.00 M x 100 mL
V1 = (2.00 M x 100 mL) / 0.100 M
V1 = 2000 mL
So, you will need to pipet 2000 mL (or 2.00 L) of the stock solution into the 100-mL volumetric flask to prepare a 2.00 M KMnO4 solution.
Similarly, you can calculate the volumes of the stock solution needed for the 5.00 M and 10.0 × 10^(-3) M KMnO4 solutions using the same formula.