What is the most common way of expressing the concentration of a solution ?
we can use it in different ways.
Molar concentration: The number of moles of solute present in a Liter of the solution.
Molal concentration: The number of moles of solute present in a Kilogram of the solution.
Mass concentration (density): The mass of solute present in the volume of the solution.
A. Concentration by Mass
The concentration of a solution may be given as the mass of solute in a given amount of solution, as in the following statements: The northern part of the Pacific Ocean contains 35.9 g salt in each 1000 g seawater. The North Atlantic Ocean has a higher salt concentration, 37.9 g salt/1000 g seawater.
B. Concentration by Percent
The concentration of a solution is often expressed as percent concentration by mass or percent by volume of solute in a solution. Percent by mass is calculated from the mass of solute in a given mass of solution. A 5%-by-mass aqueous solution of sodium chloride contains 5 g sodium chloride and 95 g water in each 100 g solution.