*2.1.2 Sodium hydroxide (NaOH)*

The laboratory grade sodium hydroxide (NaOH) solid is taken in the form of pallets (3 mm, diameter), with a specific gravity of 2.130, 98% purity. NaOH solution is prepared by dissolving the pellets in distilled water. NaOH solution of 8 M concentration (8 × 40 = 320 grams of NaOH solids per liter of the solution, where 40 is the molecular weight of NaOH) is used for preparing geopolymer. Similarly, NaOH solutions of other concentrations are prepared as discussed above.
