Materials Required:
● Pycnometer or specific gravity bottle (25 mL)
● Analytical balance
● Solvent (e.g., water, ethanol, or other liquid in which the powder is insoluble)
● Powder sample (e.g., zinc oxide, starch, or talc)
● Funnel
● Beaker
● Glass rod
● Vacuum pump (optional, to remove air bubbles)

Procedure:
● Clean and dry the specific gravity bottle (25 mL) and place the stopper.
● Weigh the empty bottle and stopper — record the weight as W₁.
● Fill the bottle completely with water (or the selected liquid) and weigh — record as W₂.
● Remove the liquid and dry the bottle thoroughly.
● Add about 5 g of the powder sample into the bottle (for heavy powders) or 1–2 g (for light powders). Weigh the bottle and powder — record as W₃.
● Slowly add the liquid to the bottle containing powder while gently swirling to avoid air entrapment. Use a vacuum pump if needed. Fill up to the mark and weigh — record as W₄.
● Process the recorded data as described below to calculate the true density.