Preparation of Sodium Hydroxide Solution

To Prepare 0.1M NaOH solution we require sodium hydroxide pellets or flakes, a beaker, a volumetric flask, distilled water, a stirring rod, and an analytical balance.

Now take about 100ml of distilled water in a 1-litre volumetric flask, then take 4.2g of NaOH and add it to the beaker containing 100 ml distilled water and stir thoroughly. Now add 700ml more distilled water again, stir, and allow to cool down to room temperature.

Finally, make up the volume to 1000ml. Keep aside for standardization.

Standardization: Now for the standardization we require potassium bipthalate (primary standard ), phenolphthalein indicator, and an already prepared sodium hydroxide solution, pipette, etc.

Now using analytical balance, accurately weigh 0.5 grams of primary standard which is already dried at 120 degrees for 120 minutes . Now dissolve the weighed quantity in 75ml of distilled water add 2 drops of indicator given above, and titrate with sodium hydroxide solution until production of permanent pink colour by filling the sodium hydroxide solution in a burette. End point is permanent pink color. Record the volume consumed.

Normality of NaOH = weight of  KHP / 0.20422*ml used of NaOH solution in titration.