Water 3.1.7

Question 1

What are the 5 key properties of water?

Answer 1

• Important metabolite
• Important solvent
• High specific heat capacity
• High specific latent heat
• Cohesion and Adhesion

Question 2

Why is water an important metabolite?

Answer 2

• It is present within hydrolysis or condensation.

Question 3

Why is water an important solvent?

Answer 3

• Water is a polar molecule and can therefore interact with other charged ions or polar molecules.

Question 4

Why does water have a relatively high specific heat capacity?

Answer 4

• Due to hydrogen bonding, it takes a lot of energy to change the temperature of water.

Question 5

Why does water have a large latent heat of vaporisation?

Answer 5

• It takes a lot of energy to break hydrogen bonds and change liquid water into a gas.

Question 6

Why is water very cohesive and adhesive?

Answer 6

• Water is cohesive as water forms hydrogen bonds with itself.
• Water is adhesive as water forms hydrogen bonds with other materials.

Question 7

Why is water being a good solvent useful?

Answer 7

• Many ions and molecules can dissolve in it.
• Provides a stable environment for aqueous organisms.

Question 8

Why is water having a high specific heat capacity important?

Answer 8

• Water doesn’t experience rapid changes in temperature and acts as a buffer to sudden changes in temperature.

Question 9

How do aquatic and terrestrial organisms benefit from a high specific heat capacity?

Answer 9

Aquatic - Can live in a thermally-stable environment where their enzymes can stay at optimum temperature.
Terrestrial - Can maintain a constant body temperature.

Question 10

Why is having a large latent heat of vaporisation?

Answer 10

• Allows water to be an excellent coolant.

Question 11

Why is cohesion and adhesion important?

Answer 11

• Cohesion allows water to create surface tension when in contant with the air.
• E.G sweat forming droplets which evaporate to cool an organism.

Question 12

Overall Exam Question:
Explain five properties that make water important for organisms.

Answer 12

1) Water has a high latent heat of vaporisation providing a cooling effect.
2) Water has a high specific heat capacity allowing the buffering of temperature.
3) Water is a good solvent allowing metabolic reactions to occur.
4) Water is a good metabolite, being essential in condensation and hydrolysis reactions.
5) Water has strong cohesion which supports columns of water in plants.