water

Question 1

type of bond between water

Answer 1

hydrogen

Question 2

what is a water molecule classed as

Answer 2

dipolar as there are charge differences

Question 3

examples of other polar differences

Answer 3

C=O (carbonyl), O-H (hydroxide)

Question 4

why is water dipolar

Answer 4

slightly negative charge on oxygen and the slightly positive charge on the hydrogen causes there to be a charge difference

Question 5

explain the specific latent heat of water

Answer 5

water has a higher boiling point due to hydrogen bonding so more energy is required to separate the molecules

Question 6

explain the latent heat of vaporisation for water

Answer 6

lots of energy is required to evaporate water

Question 7

cohesion of water

Answer 7

hydrogen bonding allows water to have strong cohesive forces allowing it to be pulled up a tube (e.g. xylem)

Question 8

surface tension of water

Answer 8

where water molecules meet the air, they are pulled back into the body of water.

Question 9

transparency of water

Answer 9

this allows aquatic plants to photosynthesise allowing light rays to penetrate through

Question 10

adhesion of water property

Answer 10

allows water to attract and interact with other substances

Question 11

function - metabolism

Answer 11

used to break down complex molecules through hydrolysis
also a raw material in photosynthesis etc

Question 12

function - universal solvent

Answer 12

water dissolves O2 and CO2, wastes like NH3 and urea, inorganic ions and small hydrophilic ions and enzymes

Question 13

function - compressibility

Answer 13

water is not easily compressed so provides support (turgor pressure in some cases)

Question 14

function - density

Answer 14

water has a high density in the liquid state so provides buoyancy as well as support to organisms living in water

Question 15

5 functions + explain of water (5)

Answer 15

-metabolite in photosynthesis etc
-a solvent so metabolic reactions can occur
-high (specific) heat capacity so buffers temp changes
-cohesion to support columns of water in plants
-cohesion so supports surface tension

Question 16

water and specific heat capacity(2)

Answer 16

has high specific heat capacity
so buffers changes in temperature

Question 17

Give two properties of water that are important in the cytoplasm of cells.
For each property of water, explain its importance in the cytoplasm.

Answer 17

1. (Universal) solvent;
   (Metabolic) reactions occur faster in solution;
2. Reactive;
   Takes place in hydrolysis / condensation / named reaction