posted by rosie on .
How do I prepare 2 L 0.1 M Hydrochloric acid from 6 M HCl ? Also how do I prepare .05 M NaOH solution from pellets? Thanks
To dilute a solution just remember that
mL1 x M1 = mL2 x M2
For solids. First you need to know how much solution you want to prepare. Let's say you want to prepare 1000 mL of 0.05M NaOH. Then you want how many moles? That will be M x L = 0.05 x 1 = 0.05 moles.
Then moles = grams/molar mass. YOu know mole and molar mass, solve for grams. Dissolve that amount of NaOH pellets in some water and make to about 1000 mL. That will give you an approximate 0.05M soln (about 1000 mL of it) but it will not be exact because you don't have NaOH in pure form. Even if you could buy 100% NaOH (and I don't think you can), the instant the bottle is opened it absorbs both moisture and CO2 from the air and becomes contaminated. The usual procedure is to prepare a solution of the approximate concn you want, then standardize the solution with a primary standard acid.