Making Soap

Coconut oil is combined with sodium hydroxide to undergo saponification and produce soap. The crude soap is then purified through salt precipitation to lower its pH and remove impurities, resulting in a safe and usable bar of soap.

1. Mix coconut oil and sodium hydroxide solution in a beaker.
2. Heat gently while stirring until water evaporates and soap forms.
3. Allow the mixture to cool and test the pH of the crude soap.
4. Add distilled water and then mix in a hot sodium chloride solution.
5. Decant the liquid using cheesecloth, leaving behind the solid soap.
6. Test and record the pH of the soap.
7. Repeat the salt wash two more times, measuring pH after each wash.
8. Add a few drops of fragrance oil and press the soap between filter paper.
9. Place the soap in a mold and allow it to dry overnight.

Science Experiment | How to make soap | Saponification | Preparation of Soap in Lab | Sodium Soap - Jagdish Kothawade:

Soap Making Tutorial and Recipe for Absolute Beginners (you can do it!) - Elly's Everyday Soap Making:

📄 The Chemistry of Clean: Make Your Own Soap to Study Soap Synthesis - Science Buddies: https://www.sciencebuddies.org/science-fair-projects/project-ideas/Chem_p096/chemistry/how-to-make-soap

📄 DIY: Make Your Own Soap - The Open University: https://www.open.edu/openlearn/science-maths-technology/science/chemistry/diy-make-your-own-soap

• Measure the pH of the liquid removed during decanting.
• Change the boiling time and compare soap yields.
• Vary the reaction temperature and measure soap yield.

• Safety glasses required.
• Gloves and lab coat or apron required.
• Sodium hydroxide is caustic and can burn skin and eyes.
• Never wear contact lenses when handling sodium hydroxide.
• If sodium hydroxide contacts skin, wash with water immediately.
• If sodium hydroxide gets in the eyes, rinse with water for at least 15 minutes and seek medical help.
• Remove and wash clothing splashed with sodium hydroxide.
• Use heat sources carefully and avoid splattering.

• What other oils can be used for soap making? (Examples include olive oil, palm oil, and soybean oil.)
• Why is potassium hydroxide sometimes used instead of sodium hydroxide? (It produces softer, liquid soaps.)
• What is a micelle? (A spherical structure formed by soap molecules in water that helps trap and remove grease and dirt.)
• What is the most common fatty acid in coconut oil? (Lauric acid.)
• How does the structure of a soap molecule make it a good cleaner? (It has a hydrophilic end that interacts with water and a hydrophobic end that binds oils and grease.)
• What is a triglyceride? (A fat molecule made of glycerol and three fatty acids.)