Which of the following is an ester:
**Question:** Which of the following is an ester:
A. Ethyl acetate
B. Propanediol
C. Glucose
D. Chloroform
**Core Concept:** Ester is a functional group in organic chemistry, specifically a carbonic acid derivative formed by the reaction between an acid and an alcohol.
**Why the Correct Answer is Right:** Ethyl acetate (A) is an ester because it contains the ester functional group (-COOR-) where R1 is ethyl (CH3CH2) and R2 is a hydroxyl group (-OH). Esterification is a reaction between an acid and an alcohol, forming an ester bond. In this case, acetic acid (from ethanol) reacts with ethanol to produce ethyl acetate.
**Why Each Wrong Option is Incorrect:**
B. Propanediol (also known as glycerol) is a sugar alcohol and not an ester. It is formed through a different process called glycerolysis, involving the reaction between glycerol and an acid.
C. Glucose (C6H12O6) is a monosaccharide sugar and not an ester. It is an essential component of carbohydrates and does not undergo the esterification reaction.
D. Chloroform (CHCl3) is a chlorinated organic compound and not an ester. It is formed through chlorination of organic compounds, not the esterification reaction involving acids and alcohols.
**Clinical Pearl:** Understanding the distinction between esters, sugars, and other organic compounds is crucial for understanding various chemical reactions and their applications in medicine, pharmacy, and biochemistry.
**Correct Answer:** A. Ethyl acetate is the correct answer because it is an ester formed through the reaction between acetic acid and ethanol, representing a fundamental concept in organic chemistry and its applications in drug synthesis, food preservation, and other industries.