Question

1. You have 510ml of 1.5 M EDTA. How much 1 mM EDTA can you make?

2. You need 0.5 L of 10% glycerol and have a bottle of 100% glycerol. How would you make it?

Answer 1

1. A Molar (M) is moles/Liter. Multiply 1.5M by 510mL (pay attention to units) and you get .765 moles. Convert .765 moles to millimoles (mmol) and you get 765 mmol, which requires 765 Liters to get a concentration of 1 milliMolar (mM). So 765 Liters is your answer.

2. If you start with 100% glycerol, then all you have to do is make sure the percent of glycerol you want is the same as the percent of glycerol in the diluted solution. So here, 10% of 0.5L is 50mL. So add 450mL of water to 50mL of 100% glycerol to get a solution of 10% glycerol.