NaOH, or sodium hydroxide, is a useful compound in the winemaking industry for testing certain qualities of wine, such as acidity. Winemakers use it in a diluted solution form when testing their wine samples. While the concentration that you require can normally be bought at a supply store, there are those who prefer to mix their own NaOH solutions from the pure substances.
Things You'll Need
Put on the gloves, goggles and lab coat. You’ll be working with potentially dangerous chemicals, so be sure to protect yourself from accidental splashes.
Determine the concentration of the NaOH solution that you need. A 0.1 or 0.2 Normality (N) is the typical concentration used for wine testing.
Measure out the amounts of NaOH and water that you will need, respectively, to make the desired concentration. The formula is dependent on the molecular weight of NaOH, and works out to about 40 grams of NaOH per liter of water to make a 1 N solution. Thus, to make a 0.1 N solution, mix 4 grams of NaOH with 1 liter of water. Gently stir the mixture with a stir stick.
Standardize the NaOH solution to accurately determine its normality. Take a flask and fill it with a HCl solution of a specified normality, at a specific measured value, like 10 ml. Then, fill a buret with 25 ml of the NaOH solution. Now, titrate the HCl solution by allowing one drop at a time from the buret to drop into the flask of HCl solution until it turns a lemon yellow color. Record the volume of the NaOH that was used by subtracting the final volume of NaOH in the buret from the initial volume.
Plug the value into this formula – (Volume of HCl used x N of HCl)/Volume of NaOH used – to derive the normality of the NaOH to a certain accuracy.
References and ResourcesIowa State University Extension; Preparing Standard Sodium Hydroxide Solution; Dr. Murli Dharmadhikari and Tavis Harris
General Chemistry Online!; How Do I Make an NaOH Solution of Specified Normality?;Fred Senese