Stock Solution
A concentrated solution prepared in advance and stored for later dilution to working strength.
Unit
mol/L
In depth
Preparing a stock saves repeated weighing, improves reproducibility and reduces the storage volume required. Its concentration is verified by standardisation against a primary standard, and any degradation during storage — by evaporation, photolysis or absorption of atmospheric CO₂ — must be allowed for.
Examples in the real world
A 1.0 M NaOH stock diluted as needed; a 1000 ppm metal standard supplied for instrument calibration.