Water's High Latent Heat Enables Efficient Cooling via Evaporation

Steps:

• Sweating produces water on the skin that evaporates to remove heat.
• Evaporation requires energy to break intermolecular bonds, absorbed from the body.
• The property determining energy per unit mass during phase change is latent heat of vaporization.
• High value means more heat removed per gram of sweat evaporated.

Why A is correct:

• Latent heat of vaporization is the energy (about 2260 J/g) needed to vaporize water at constant temperature, allowing significant body heat loss without much sweat volume.

Why the others are wrong:

• B: Specific heat capacity (4.18 J/g°C) governs heat absorption for temperature rise in liquid water, not phase change during evaporation.
• C: Hydrogen bonding enables four bonds per molecule, contributing to cohesion but not directly to the heat absorbed in vaporization.
• D: High cohesion and adhesion cause surface tension, aiding capillary action but irrelevant to evaporative heat loss.

Final answer: A