1 Answer

Since "normality" is defined as the gram equivalent weight of a substance in a liter of solution, a 0.02 N NaOH solution would have 0.02 gram equivalents of NaOH per liter. To reduce it to 0.01 N you need only dilute it to one half of the original - e.g. 500 ml of NaOH mixed with 500 ml of pure water. Because there is a small change in the density upon mixing, the exact amount of water will differ slightly from 500 ml, but for a solution as dilute as 0.02 N, it won't be that far off. The best way to get it exact would be to start with a known volume of 0.02 N NaOH and then add enough water to bring the total to exactly twice the original volume. This might be accomplished by doing it in a graduated cylinder or adding it from a burette into a volumetric flask. the important thing is to know the starting volume of the 0.02 N solution and the final volume of the diluted (0.01 N) solution