AP BIOLOGY

Detailed explanation-1: -Water molecules are very good at forming hydrogen bonds, weak associations between the partially positive and partially negative ends of the molecules. Hydrogen bonding explains both the effectiveness of evaporative cooling (why sweating cools you off) and the low density of ice (why ice floats).

Detailed explanation-2: -Evaporation has a cooling effect. When a molecule evaporates it separates from other molecules in a liquid and becomes a vapour molecule. Large amounts of heat are needed to evaporate water, because H-bonds need to be broken. Sweating is an example of using water as a coolant.

Detailed explanation-3: -Water’s high heat capacity is a property caused by hydrogen bonding among water molecules. When heat is absorbed, hydrogen bonds are broken and water molecules can move freely.

Detailed explanation-4: -One unique property of water is its high heat of vaporization. Heat of vaporization refers to the energy required to convert one gram of liquid into a gas at boiling point. This required energy will break down the intermolecular attractive forces in water.

Detailed explanation-5: -Answer and Explanation: The cooling effect of water is due to water having a high specific heat. this high specific heat allows water to absorb excessive amounts of energy without a change in temperature.