1.5 molar edta, 2molar tris,, how much do i need of each to make a solution that consists of 50mM edta, ...?

Question

and 50mM tris and 50% glycerol?

Answer 1

The exact amounts will depend on the total volume of the solution you're making. Since the final concentration of the Tris is 50 mM and your stock is 2M, you will need 50/2000 * [final total volume] of the 2M stock. The calculation for the EDTA is similar: 50/1500 * [final total volume] of the 1.5M stock. The glycerol, of course, is easy. The rest of the solution is presumably water. So, if you're making 1 liter of solution, you will need 25 mL of 2M Tris, 33.33 mL of 1.5M EDTA and 500 mL of 100% glycerol, right? Don't forget to use those amounts to "back-calculate" to make sure the answer is correct!