I see. I will try to get my manufacturer to change his definition methods because some other hive member marked it being madness to state a concentration as weight per volume.........
but I think I will stockpile lots of their old bottles before doing so; cuz I can live very well with this "nonsense", at least better than with weighing any solution I want to use...
Last example for anyone who is as "unlucky" as I am and has lying around any acid, with a strenght given in weight/volume:
33% w/v -> 33 percent of the amount of solution is the amount of the dissolved compound
in weight, meaning 1000(ml) contain 330(g) - and 1 part is therefore 1g
or 1ml, depending on what is meant - it just tells about the relations of plain numbers, not about the relations between the units they stand for...
100 parts * volume = 33 parts * weight | / 10
10 parts (* volume) = 3.3 parts (* weight)
10 (ml) = 3.3 (g)
scientific enough? Only disadvantage is that you have to check the density for being able to calculate how much solvent 10ml contain:
10(ml) * X (density g/ml) - 3.3(g) = Y(g)
Y(g) * Z (density of solvent) = Y2(ml) <-- volume of remaining solvent contained in 10ml of a 33% w/v solution
And I still don't know why I learned time ago that solutions with a certain concentration are made by dissolving the compound in a small amount of solvent and then diluting to a certain volume!?! Any ideas on why universities consider it the right thing to teach their students how to make w/v solutions??
A