If the density of ocean water at a depth of 1.00 x 104 m is 1.071 g/mL and if 20.0 g of water at that depth contains 197mg of potassium chloride, what is the molarity of potassium chloride in the sample? It wants it in M.

Answer 1

what is the volume of 20 g of water?
20 g /1.071 g/mL = 18.674 mL
so
197 *10^-3 g KCl /18.674*10^-3 L
= 10.55 grams/liter

Mol mass of KCl = 74.5 grams/mol

(10.55 grams/Liter)/74.5 grams/mol
= .142 mols/Liter