Water

Question 0

Cohesion

Answer 0

-The H-bonding of hydrogen and oxygen between molecules

Question 1

Structure of water molecule (3)

Answer 1

• Two hydrogens covalently bonded to an oxygen
• Higher electronegativity around oxygen causes electrons to spend more time at the oxygen
• This gives the hydrogen delta plus and minus charges, thus they are polar

Question 2

Adhesion

Answer 2

-The attraction between water molecules and objects

Question 3

Hydrogen bonds (2)

Answer 3

• Weak bond between hydrogen and oxygen

- Strong when the molecule forms a lattice

Question 4

Hydrolysis

Answer 4

-The splitting of bonds using water

Question 5

Physical property of water: good solvent (4)

Answer 5

• Ions and charged molecules can dissolve in water
• Nutrients can be transported in the water and can be transported in the blood
• toxic substances like ammonia from excretion can be diluted
• Chemical reactions e.g respiration can occur in cells

Question 6

Physical property of water: transparency (3)

Answer 6

• Light travels through water
• Sunlight can travel through water for photosynthesis
• See prey and predators

Question 7

Physical property of water: high specific heat capacity (3)

Answer 7

• A lot of energy is needed to raise the temperature (overcome H-bonds)
• Enables environment to thermoregulate
• Biological reactions occur at a constant rate

Question 8

Physical property of water: high latent heat of vaporisation (3)

Answer 8

• The energy needed to change the state from liquid to gas is high
• Evaporation removes heat from surface
• Sweating and panting removes heat from land mammals

Question 9

Physical property of water: cohesion tension (2)

Answer 9

• The attraction of water molecule to water molecule

- Allows capillary action and the transpiration stream to occur

Question 10

Physical property of water: surface tension (2)

Answer 10

• Allows pond skaters to skate wild and free

- Causes the dome like structure in water

Question 11

Physical property of water: metabolic

Answer 11

-Water takes part as a reactant in some chemical processes e.g. Hydrolysis and photosynthesis