Which property of water is demonstrated when humans sweat to cool down?

• A. Universal solvent
• B. High heat of vaporization
• C. Low density as a solid
• D. Cohesion

Answer: (B)

Verified step by step guidance

1. Understand the concept of 'high heat of vaporization': This property refers to the amount of energy required to convert water from a liquid to a gas. Water has a high heat of vaporization due to the strong hydrogen bonds between its molecules.
2. Relate this property to sweating: When humans sweat, the water in sweat absorbs heat from the body to break the hydrogen bonds and evaporate. This process removes heat from the skin, cooling the body down.
3. Eliminate other options: 'Universal solvent' refers to water's ability to dissolve many substances, which is unrelated to cooling through evaporation. 'Low density as a solid' describes ice floating on water, which is also unrelated. 'Cohesion' refers to water molecules sticking together, which does not directly explain cooling through sweat.
4. Focus on the correct answer: The cooling effect of sweating is directly tied to water's high heat of vaporization, as it requires significant energy to evaporate, effectively removing heat from the body.
5. Conclude the explanation: The property of water demonstrated when humans sweat to cool down is its high heat of vaporization, as this process is essential for regulating body temperature through evaporative cooling.