Final answer:
Neutralization involves an acid reacting with a base to produce water and a salt. Water of crystallization is water molecules included in the structure of a compound. Efflorescence, deliquescence, and hygroscopy are processes related to the absorption or release of water by substances.
Step-by-step explanation:
Neutralization is a chemical reaction wherein an acid and a base react to form water and a salt. This is an important reaction in chemistry, often occurring when, for example, hydrochloric acid (HCl) reacts with sodium hydroxide (NaOH) to form sodium chloride (NaCl, commonly known as table salt) and water (H2O).
Water of crystallization refers to water molecules that are included in the crystalline structure of a compound, usually salts. For instance, copper sulfate pentahydrate (CuSO4·5H2O) has five molecules of water of crystallization.
When a hydrate loses its water of crystallization to the atmosphere upon exposure to air, it is referred to as efflorescence. Sodium sulfate decahydrate (Na2SO4·10H2O) often undergoes efflorescence in dry air, losing its water and turning into the anhydrous form.
Deliquescence occurs when a substance absorbs moisture from the air until it dissolves itself, becoming a solution. Calcium chloride (CaCl2) is highly deliquescent and is used as a drying agent.
Hygroscopy is the ability of a substance to attract and hold water molecules from the surrounding environment. Silica gel, often found in little packets inside product packaging, is used because of its hygroscopic properties to control humidity and avoid spoilage or damage to the product.