Question

which best describes what occurs in a dehydration reaction?
a water molecule is removed from a molecule when it creates a covalent bond.
a covalent bond is broken by adding an oh to one side of the molecule and an h to the other side.
a bicarbonate group is exchanged for an anion like chlorine.
electrons are removed from a molecule and energy is released.

Explanation:

A dehydration reaction involves the removal of a water molecule when a covalent bond is formed. The other options describe different types of reactions. Adding an OH and an H to break a covalent bond is hydrolysis. Exchanging a bicarbonate group for an anion is an ion - exchange reaction. Removing electrons and releasing energy is an oxidation - reduction reaction.

Answer:

A. A water molecule is removed from a molecule when it creates a covalent bond.