Question

give the practical details of how you would prepare a 0.5M hydrochloric from a stock of 34%(w/w)with relative density of 1.18.

Answer 1

First calculate the molarity of the HCl furnished. That will be
1000 mL x 1.18 g/mL x 0.34 = about 400 g
moles HCl = grams/molar mass = about 400/36.5 = about 11M
Then you need to decide how much of the 0.50M soln you want. If you want 1000 mL, then you want mL x M = mL x M
mL x 11 = 1000 x 0.5 and solve for mL of the 11 M soln.
How to make it up? Take ? mL of the 11 M soln, place in a 1 L volumetric flask, add was to the mark, shake thoroughly.