⚗️ Standard Solution Preparation Calculator

Preparing standard solutions in the lab

A standard solution is a solution of precisely known concentration, prepared either by dissolving a weighed mass of solid reagent in solvent up to a fixed volume, or by carefully diluting a concentrated liquid reagent of known purity and density. For solids, the required mass follows mass = concentration × volume × molar mass (for molar concentrations), or a direct scaling for mg/mL and % w/v. For concentrated liquid reagents such as acids and bases, the stock's own molarity must first be derived from its density and percentage purity (assay), since commercial concentrated reagents are sold by weight percentage rather than molarity. Always prepare solutions in a volumetric flask rather than a graduated cylinder when precision matters, and always add concentrated acid to water rather than the reverse to control the exothermic reaction safely. For thesis reporting: state the reagent, its purity/grade, the mass or volume measured, the solvent, and the final volume. Example: 'A 0.1 M NaCl standard solution was prepared by dissolving 2.922 g NaCl (ACS grade) in deionized water to a final volume of 500 mL.'