Question 66

The Correct Answer is B **Explanation for Option B (evaporation):** Evaporation is the process by which a liquid turns into a gas or vapor, usually occurring when the liquid absorbs heat. In the described scenario—boiling seawater to create freshwater vapor and brine—heat is applied (boiling) to cause the liquid water molecules to change phase into gaseous water vapor. This physical separation process, where water changes from liquid to gas, is fundamentally **evaporation** (or vaporization, which is evaporation accelerated by boiling). **Why the other options are incorrect:** * **A) condensation:** Condensation is the opposite of evaporation. It is the process where a gas or vapor turns back into a liquid (e.g., cooling the freshwater vapor to collect liquid freshwater). It is the second step in distillation, not the initial separation step. * **C) dehydration:** Dehydration is the process of removing water from a substance or organism. While the process *results* in dry air/vapor (or concentrates the brine), the specific physical mechanism used to separate the water from the salt by heating/boiling is defined as evaporation. * **D) dissolution:** Dissolution is the process where a solute (like salt) is dissolved into a solvent (like water) to form a solution. Since the sea water is already a solution, and the goal is to *reverse* the mixing by separating the components, dissolution is entirely incorrect.