Sodium hydroxide (NaOH), or Lye, is a common element in many science projects, especially chemical experiments, as well as in homemade soap and wine. This is also a caustic chemical, so it's not easy to find in stores like it used to be.
Some shops carry it as Red Devil lye with laundry supplies. It's also found, usually in an impure form, in solid drain cleaners. Craft stores carry lye for soapmaking. There is also food-grade sodium hydroxide, sold in some specialty cooking stores. You can buy sodium hydroxide online.
You can purchase it as sodium hydroxide or lye, pure lye drain opener, caustic soda, and pure or food-grade sodium hydroxide. Depending on your project, you might be able to replace potassium hydroxide (KOH), which has similar chemical properties and is easier to find. However, these two chemicals are not the same, so if you make substitutions, expect a slightly different result.
How to make sodium hydroxide
If you can't buy sodium hydroxide, you can use a chemical reaction to make it. You will need:
- Table salt (sodium chloride, not dimiated)
- 2 carbon electrodes (from zinc-carbon batteries or graphite pencil leads)
- Crocodile clip.
- Power supply (like a 9-volt battery)
In a glass container, stir the salt into the water until dissolved. Do not use aluminum containers or aluminum equipment because sodium hydroxide will react and damage it. Place two carbon stems in the container. Use the crocodile clip to connect each stem to the battery terminal.
Let the reaction last for about seven hours. Place the settings in a well-ventilated room, because hydrogen gas and chlorine will be produced. The reaction produces a hydroxide sodium solution. You can use it or you can evaporate it from water to focus the solution or get a solid Lye.