During the evaporation of a saltwater solution, what happens to the salt?

• A. The salt chemically reacts with water to form a new compound.
• B. The salt decomposes into its constituent elements.
• C. The salt remains as a solid residue after the water evaporates.
• D. The salt evaporates along with the water.

Answer: (C)

Verified step by step guidance

1. Understand the nature of the saltwater solution: it is a mixture of salt (usually an ionic compound like NaCl) dissolved in water, where salt dissociates into ions but does not chemically react with water under normal conditions.
2. Recall the process of evaporation: when water evaporates, it changes from liquid to gas, leaving behind any non-volatile substances dissolved in it, such as salt.
3. Recognize that salt has a much higher boiling point than water and does not evaporate at the temperature at which water evaporates.
4. Conclude that as water evaporates, the salt ions come back together to form solid salt crystals, which remain as a solid residue.
5. Therefore, the salt does not chemically react, decompose, or evaporate; it simply remains as a solid after the water has evaporated.