What is a condensation reaction?

• A. When 2 monomers combine and a small molecule is produced.
• B. When the double bond breaks to form a bond with another atom
• C. When monomers break apart into atoms
• D. When water is added to break a bond

Answer: (A)

A condensation reaction is when two smaller molecules join to form a larger molecule and a small molecule is released in the process, usually water. This loss of a tiny molecule during bond formation is what distinguishes condensation (or dehydration synthesis) from other types of reactions. The option that states two monomers combine and a small molecule is produced matches this idea exactly. The other descriptions refer to different processes: breaking a double bond to bond with another atom describes a different bond-changing process, breaking a substance into atoms is decomposition, and adding water to break a bond is hydrolysis, which is the opposite of condensation.