Hydrolysis of an ester in presence of alkali is called

Options

A. esterification
B. saponification
C. substitution
D. addition

Explanation

### Step-by-Step Solution:

1. **Understanding Hydrolysis of Esters**:
- Hydrolysis refers to the reaction of a compound with water, leading to the breakdown of that compound. In the case of esters, hydrolysis involves breaking the ester bond to form an acid and an alcohol.

2. **Identifying the Role of Alkali**:
- When hydrolysis occurs in the presence of an alkali (like sodium hydroxide, NaOH), it is termed alkaline hydrolysis. The alkali facilitates the reaction and helps in the complete conversion of the ester.

3. **Chemical Reaction**:
- Consider an ester represented as RCOOR' (where R and R' are hydrocarbon chains). When this ester reacts with NaOH and is heated, the reaction can be represented as:
\[ RCOOR' + NaOH \rightarrow RCOONa + R'OH \]
- Here, RCOONa is the sodium salt of the carboxylic acid (sodium carboxylate), and R'OH is the corresponding alcohol.

4. **Products of the Reaction**:
- The products of this reaction are:
- A sodium carboxylate (RCOONa)
- An alcohol (R'OH)

5. **Naming the Process**:
- The process of hydrolyzing an ester in the presence of an alkali is specifically known as **saponification**. This term is derived from the fact that the sodium salt produced in the reaction is a soap.

6. **Conclusion**:
- Therefore, the hydrolysis of an ester in the presence of alkali is called **saponification**.