Lesson 11 of 15
An ester and an alkali
Show on a big screenSoap is made from fat or oil and an alkali. An alkali is a base that dissolves in water. The reaction has a name.
Step 1 of 4
- An ester meets sodium hydroxide, an alkali.
- The ester breaks.
- It gives an alcohol and the sodium salt of the acid.
- The sodium salt of a long-chain acid is a soap.
Loading lab…
Read the two reactants. Tap the name of the reaction.
The rule
An ester and sodium hydroxide make an alcohol and a salt. The salt is the sodium salt of the acid. This is saponification. Fats and oils treated this way give soap.
CH₃COOCH₃ + NaOH → CH₃OH + CH₃COONa
This reaction is saponification. It breaks an ester into an alcohol and a salt.
Fats and oils are esters of long-chain acids. The sodium salts of those acids are soaps.
| Start | Add | Name |
|---|---|---|
| Acid | Alcohol | Esterification |
| Ester | Sodium hydroxide | Saponification |
| Acid | Sodium hydroxide | Neutralisation |
Try the lab to finish this lesson.