Question

Important equations for making up solutions Weight of solute (g) = formula weight of solute (g/mole) x molarity (mol/l) x final volume (L) C1V1 = C2V2

How to make solutions

Choose the correct formula from above. Please show all the steps and be sure to clearly show what values are being using relating to the formula.

Serial Dilution Technique: Starting with your solution of 2mM KMnO₄, make 6 ml of each of the following concentrations: 1.0 mM, 0.5mM, 250 µM, 125 µM, 62.5 µM, 31.3 µM, and 15.6 µM.

1. Determine how much solution you will transfer from one tube to the next and how much water needed to dilute to get the appropriate concentration.

Answer 1

Solution:

1) 1 mM solution:

C1V1 = C2V2

2 mM x V = 1 mM x 6 mL

V = 3 mL

2) 0.5 mM solution:

2mM x V = 0.5 mM x 6 mL

V = 1.5 mL

3) 250 uM solution:

250 uM = 0.250 mM

Thus,

2 mM x V = 0.250 mM x 6 mL

V = 0.75 mL

4) 125 uM solution = 0.125 mM

2 mM x V = 0.125 mM x 6 mL

V = 0.375 mL

5) 62.5 uM = 0.0625 mM

2 mM x V = 0.0625 mM x 6 mL

V = 0.188 mL

6) 31.3 uM = 0.0313 mM

2 mM x V = 0.0313 mM x 6 mL

V = 0.094 mL

7) 15.6 uM = 0.0156 mM

2 mM x V = 0.0156 mM x 6 mL

V = 0.047 mL