posted by Raul .
which is more concentrated a 1 liter solution containing 30 g of NaCl or a 1 liter solution containing 30g of KCl
moles NaCl = grams/molar mass
moles KCl = grams/molar mass
M = moles/L.
Which has the larger number of moles.
By the way I should point out that this question is a little misleading. If you are talking about % by volume, then 30g/L soln and 30 g/L soln are the same concn. Molarity differs because 30 g of each gives a different number of moles.