Question

What would be the concentration of a solution resulting when you dissolve 4.725g of nacl (molar mass = 58.45) in water to make a solution with a final volume of 500.0 ml?

Answer 1

There are a number of ways to express concentration of a solution. This includes molarity. It is expressed as the number of moles of solute per volume of the solution.  To convert the mass of the solute to moles, we use the molar mass of the substance. We calculate as follows:

MOlarity = 4.725 g ( 1 mol / 58.45 g ) / .5 L = 0.162 mol / L