Final answer:
3) NaOH
Sodium hydroxide (NaOH), also known as lye or caustic soda, is the base often used in soap making. It is essential for the saponification process, where it hydrolyzes fats and oils to create soap and glycerol.
Step-by-step explanation:
The base often used in soap making is sodium hydroxide, NaOH, also known as lye or caustic soda. This compound is instrumental in the soap-making process through a reaction known as saponification, where fatty acids from fats and oils are converted into soap in the presence of a strong base such as NaOH or KOH, potassium hydroxide.
Sodium hydroxide is highly effective in this process due to its ability to hydrolyze the ester bonds in the fats, leading to the formation of soap and glycerol.