Water Properties

Homework pack 8 - Gas Exchange in Plants

Water has a high surface tension. Why is this useful for organisms?

It can support the mass of organisms such as pond skaters by adhesive forces. It also means water can be pulled through plants.

Explain what is meant by a high specific heat capacity of water

A large amount of energy is required to increase 1kg of water by 1C

Water has cohesive properties. What is meant by cohesion?

Water will form hydrogen bonds to other water molecules.

Water has adhesive properties. What is meant by adhesion?

Water will form hydrogen bonds with other polar or charged molecules.

Water is transparent. Why is this useful for organisms?

Light can pass through water to aquatic plants for photosynthesis.

Water has a high specific heat capacity. Why is this useful for organisms?

Aquatic habitats and the cytoplasm of cells remain a stable temperature.

Water has a high specific latent heat. Why is this useful for organisms?

It acts as a coolant (e.g. sweating) and aquatic habitats don’t evaporate easily.

Explain what is meant by a high specific latent heat of water.

A large amount of energy is required to change the state of 1kg of water.

Water is a liquid at most temperatures on Earth. Why is this useful for organisms?

It can be used as a medium for chemical reactions and to help transport chemicals.

Ice is less dense than water. Why is this useful for organisms?

Ice forms an insulating layer over aquatic habitats. So animals in the water can still move/swim.