Chapter 3 - water

Question 1

what are the characteristics of water?

Answer 1

• high boiling point: due to hydrogen bonding between water molecules
  -freezes to become less dense: hydrogen bonds fix polar molecules further apart than average distance in liquid. produce giant, rigid, open structure
• cohesive properties: water molecules are attracted to each other
• adhesive properties: water molecules are attracted to other materials

Question 2

why is water important for life?

Answer 2

• acts as a solvent: many solutes in an organism can be dissolved
• efficient transport medium: cohesion and adhesion exhibit capillary action (water can rise up narrow tubes against the force of gravity)
• acts as a coolant: buffer temperature changes during chemical reactions in cells
• is stable: does not change temp or become gas easily so provides a constant environment