How can I calculate the percent concentration of a solution?

Question

Luna Chen · Accepted Answer

The most widely used unit of measurement for any solution's percentage concentration is mass percent: (Mass of the component in the solution / Total mass of the solution) x 100 is the mass percentage of any component in the solution. Additional techniques are: Volume percentage of a component is calculated as (component volume/total volume of solution) x 100. Specifically, Mass by Volume percentage is equal to (Solute mass in grams/Solution volume in milliliters) x 100. Remember this: Don't make the mistake of using the mass or volume of just the solute or solvent in the denominators of the above expressions; instead, add the corresponding masses and volumes of ALL the components of the solution whenever we refer to the mass or volume of the solution. Most of the time, a solution's concentration is expressed as the number of moles of solute (also known as molarity) present in one liter of the solution. (If you would like to express concentration in another way, please click this link.) EXAMPLE:
(a) If 25 moles of NaCl are present in 100 L of a solution wherein H2O is the solvent, then the concentration of the solution is  #25/100=0.25 "mol·L"^-1#. (b) How much water is needed to dissolve 15.0 g of sodium hydroxide in order to create 225 mL of solution? What is the molarity of this solution? Resolution Moles of NaOH = 15.0 g NaOH × #(1"mol NaOH")/(40.00"g NaOH")# = 0.375 mol NaOH Volume = 225 mL × #(1"L")/(1000"mL")# = 0.225 L soln Molarity = #(0.375"mol")/(0.225"L")# = 1.67 mol/L

Xavier Avery · Answer

undefined Percent concentration of a solution can be calculated using the following formula:

Percent Concentration = (Mass of solute / Volume of solution) * 100