AL chem hydrolysis of ester

Both acid and alkali can be used in hydrolysis to convert an ester (RCOOR') to the corresponding carboxylic acid (RCOOH) and alcohol (ROH).

In acid hydrolysis, the mixture and the ester and dilute sulphuric acid is heated under reflux.
RCOOR' + H2O ⇌ RCOOH + R'OH
RCOOH and R'OH are separated using fractional distillation.
Acid hydrolysis is seldom used to convert RCOOR' to RCOOH and R'OH, because the reaction is reversible and thus RCOOR' CANNOT be completely converted to RCOOH and R'OH.

In alkali hydrolysis (saponification), the mixture of the ester and sodium hydroxide solution is heated under reflux.
RCOOR' + NaOH → RCOONa + R'OH
The alcohol R'OH is firstly separated from the reaction mixture by fractional distillation. An excess of a dilute mineral acid (usually dilute sulphuric acid) to convert RCOONa to RCOOH, which is the separated by fractional distillation.
Alkali hydrolysis is usually used to convert RCOOR' to RCOOH and R'OH. Although the process looks complicated, the yield is much higher than that of acid hydrolysis. This is because alkali hydrolysis is an irreversible reaction and theoretically RCOOR' is completely hydrolyzed.

The answer does not involve the mechanisms of the acid hydrolysis and alkali hydrolysis.

2011-01-24 02:05:50 補充：
In both acid hydrolysis and alkali hydrolysis, heat is needed. In room temperature, the reactions are slow, and it will take a few days to reach the equilibrium state or to complete the reaction.

用acid or alkaline會比有水有效,但如果用alkaline做hydrolysis of ester就要加熱,但可以完全hydrolysis ester,用acid就不必加熱,但reaction會是equilibrium