volume is known, same equation as case 1. VA=Vt; mB = C VA /100 Example: Make 2 g/100mL of NaCl solution with 1 L water. The density of the resulting solution is considered to be equal to that of water, statement holding especially for dilute solutions, so the density information is not required. mB = C VA = ( 2 / 100 ) g/mL × 1000 mL = 20 g Chemists often make concentrated stock solutions that may then be diluted as needed for laboratory applications. Standard solutions are those where concentrations of solutes are accurately and precisely known. See also is a common term in a range of disciplines, and can have different meanings depending on the analytical method used. In water quality, it refers to the amount of residue remaining after the evaporation of water from a sample. References External links Homogeneous chemical mixtures Alchemical processes Physical chemistry Colloidal chemistry Drug delivery devices Dosage forms