Water：练习题

• a.

  Hydrogen bonds between water molecules create surface tension that allows the mammal to sweat without losing essential ions.

• b.

  The high density of water allows it to support the weight of the mammal while swimming in aquatic environments.

• c.

  Water acts as a buffer against rapid internal temperature changes because it requires a lot of energy to raise its temperature by \(1^{\circ}C\).

• d.

  Evaporation of a small amount of water from the skin surface removes a large amount of body heat, providing an effective cooling effect.

• a.

  Strong cohesive forces caused by the small molecular mass of water.

• b.

  Solvent properties due to the ability of water to form ionic bonds with solutes.

• c.

  High latent heat of vaporisation due to the polarity of the oxygen-hydrogen bonds.

• d.

  High specific heat capacity due to the presence of many hydrogen bonds between molecules.

• a.

  High surface tension caused by the evaporation of water at the stomata, which pushes the water column upwards from the roots.

• b.

  Low viscosity caused by the lack of polarity in water molecules, allowing them to slide past one another easily under pressure.

• c.

  Strong cohesion caused by hydrogen bonding between the slightly positive hydrogen of one molecule and the slightly negative oxygen of another.

• d.

  Adhesion caused by covalent bonding between water molecules and the lignin in the cell walls of the xylem vessels.

• a.

  The polar nature of water allows it to act as a universal solvent for salts found in sweat, facilitating evaporation.

• b.

  Water has a high specific heat capacity, meaning it can absorb a lot of thermal energy without its own temperature rising significantly.

• c.

  Strong cohesive forces between water molecules prevent them from evaporating too quickly, prolonging the cooling effect.

• d.

  A large amount of energy is required to break the hydrogen bonds between water molecules to turn liquid water into water vapour.

• a.

  The formation of hydrogen bonds between water molecules, creating high cohesive forces.

• b.

  The ability of water to act as a metabolite in condensation reactions within the tracheids.

• c.

  The relatively high specific heat capacity which prevents density changes in the xylem.

• d.

  The high latent heat of vaporisation which prevents the water column from boiling.

先自己写一遍答案，再对照解题步骤。

先自己写一遍答案，再对照解题步骤。

先自己写一遍答案，再对照解题步骤。