Water

Question 1

What type of bonding is in water?

Answer 1

Covalent bonding

Question 2

What type of molecule is water?

Answer 2

Polar

Question 3

What bonds are in water?

Answer 3

Hydrogen

Question 4

Are hydrogen bonds weak or strong?

Answer 4

Weak but if there are many, they form a strong structure

Question 5

Why does water have many essential roles in living organisms?

Answer 5

Because of the polarity of water molecules
The presence and number of hydrogen bonds between water molecules

Question 6

What charge is oxygen?

Answer 6

Weak negatively charged

Question 7

What charge is hydrogen?

Answer 7

Weak positively charged

Question 8

Why do hydrogen bonds form?

Answer 8

Between the positive and negatively charged regions of adjacent water molecules

Question 9

What dissolves in water?

Answer 9

Many ions (NaCl) and polar molecules e.g. glucose amino acids

Question 10

What does water being a solvent allow?

Answer 10

Allows chemical reactions to occur as dissolved solutes are more chemically reactive when they are free to move

Question 11

What does water being a solvent allow for metabolites?

Answer 11

They can be transported efficiently (except non-polar molecules as they are hydrophobic)

Question 12

What does the solvent allow into and out of cells?

Answer 12

Diffusion

Question 13

What does water having its maximum density at 4 degrees Celsius do for ice?

Answer 13

Ice floats on cold water

Question 14

What does water having a maximum density at 4 degrees Celsius do for the water layer underneath?

Answer 14

Insulates the water layer underneath- leaving liquid water as a habitat

Question 15

Metabolite?

Answer 15

A reactant or product in many key reactions e.g. hydrolysis, condensation, photosynthesis, respiration
Enables all chemical reactions to occur

Question 16

What is SHC?

Answer 16

The energy required to increase the temperature of water by 1 degrees Celsius per gram

Question 17

Does water have a high or low SHC?

Answer 17

High

Question 18

Is a large or small amount of energy needed to raise water’s temperature?

Answer 18

A large amount

Question 19

How many hydrogen bonds are there in water?

Answer 19

2 hydrogen bonds per water molecule

Question 20

What is required for these hydrogen bonds to break?

Answer 20

A lot of thermal energy and a lot of energy to build these bonds

Question 21

Does the temperature of water fluctuate a lot?

Answer 21

Not much

Question 22

What are the advantages of a high SHC for living organisms?

Answer 22

Provides suitable habitats
Able to maintain a constant temperature- water is able to absorb a lot of hear without big temperature fluctuations
Maintain temperature for enzyme activity

Question 23

What does water in blood plasma do?

Answer 23

Transfers heat around the body to maintain a constant temperature

Question 24

Adhesion?

Answer 24

Water is able to hydrogen bond to other molecules- enables water to move up the xylem due to transpiration

Question 25

What is latent heat of vaporisation?

Answer 25

The energy required to change states

Question 26

Does water have a high or low latent heat of vaporisation?

Answer 26

High

Question 27

What must occur in order for changes of state to occur?

Answer 27

A large amount of energy must be absorbed by water to break the hydrogen bonds and evaporate

Question 28

How is the high latent heat of vaporisation an advantage for living organisms?

Answer 28

Only a little water is required to evaporate for the organism to lose a great amount of heat Provides a cooling effect for organisms (transpiration or evaporation of sweat) -> thermoregulation

Question 29

Why do water molecules stick together?

Answer 29

Due to lots of hydrogen bonds

Question 30

What does the strong cohesion allow for in the xylem?

Answer 30

Water moves in an unbroken column/stream

Question 31

How does water get a firm surface?

Answer 31

Due to cohesion between water molecules

Question 32

How is a film created on the top of the water?

Answer 32

A body of water meets the air, these hydrogen bonds occur between the top layer of water molecules to create a film on top of the water

Question 33

What does surface tension allow for leaves and small organisms?

Answer 33

Leaves can float on the water and small organisms can move across the surface