Seawater Purification Using Desalination and Distillation

Steps:

• Seawater's high salt content requires removal for drinking.
• Desalination broadly removes salts through various methods.
• Fractional distillation evaporates seawater and condenses pure water vapor, separating it from salts.
• Both processes combine in thermal desalination to yield potable water.

Why C is correct:

• Desalination is the overarching process of salt removal, while fractional distillation is a specific thermal method defined by successive vaporization-condensation cycles to purify seawater efficiently.

Why the others are wrong:

• A: Desalination is required to eliminate salts; omitting it leaves water undrinkable.
• B: Fractional distillation is a core technique in thermal desalination plants for seawater.
• D: Both processes are necessary; neither alone suffices for effective purification.

Final answer: C