Water

Question 1

Structure of water

Answer 1

1 atom of oxygen + 2 atoms of hydrogen

Question 2

What type of bonds are in a water molecule

Answer 2

Covalent

Question 3

What charge does the oxygen atom have in water
What charge does the hydrogen atom have in water

Answer 3

Negative
Positive (both)

Question 4

Because the charges in water are opposite what type of molecule is it

Answer 4

Polar molecule

Question 5

What are the forces of attraction between different water molecules called + strength

Answer 5

Hydrogen bonds
Weak but have a large number so large effect on the properties

Question 6

Properties of water x4

Answer 6

• high specific heat capacity
• high latent heat of vapourisation
• great solvent
• good in metabolic reactions

Question 7

Why is water good habitat for aquatic organisms to do with specific heat capacity

Answer 7

• very high specific heat capacity
• the energy put in goes to breaking hydrogen bonds rather than increasing kinetic energy of water molecules
• water acts as a buffer to rapid temperature change
• if the temperature changed to rapidly organisms would not function properly

Question 8

Is ice more or less dense then water
Properties of ice

Answer 8

Ice is less dense so it floats
Insulate water below stops it freezing - organisms can continue living

Question 9

Benefit of water having a high specific lanterns heat

Answer 9

Organisms can cool without losing a great deal of water
Eg. Sweating

Question 10

Because water is such a good solvent what can it be used as + example

Answer 10

Transport substances
Eg. Blood plasma
Transport in xylem
Eg. Mineral ions

Question 11

What is water molecules sticking together called + why do they do this

Answer 11

Cohesion
Due to hydrogen bonds

Question 12

Why is cohesion of water a benefit in xylem

Answer 12

Allows long columns of water to travel in xylem tubes

Question 13

Benefit of cohesion on eg ponds

Answer 13

Cohesion causes surface tension where water meets air
This allows it to act as a habitat

Question 14

Example of reactions water is used for

Answer 14

Hydrolysis
Photosynthesis

Question 15

Where is water produced which reactions

Answer 15

Condensation reactions
Aerobic respiration

Question 16

Water is a ….. solvent

Answer 16

Good

Question 17

What has a relatively.,.. specific heat capacity

Answer 17

High

Question 18

Water has relatively …. Latent heat of vaporisation

Answer 18

high

Question 19

Water is ….. dense when solid

Answer 19

Less

Question 20

Water has …. surface tension and c…

Answer 20

high
Cohesion

Question 21

What are the key properties of water that make it essential to living organisms x5

Answer 21

As a solvent allowing the transport of substances
High specific heat capacity so buffers changes in temperature
Large latent heat of vaporisation so provides cooling effect
Cohesion so produces surface tension for small organisms
Cohesion so imports columns of water

Question 22

When is water used in metabolism + what does the water do x2

Answer 22

Hydrolysis molecule of water breaks bond
Condensation releases water molecule

Question 23

Explain why water is a good solvent

Answer 23

Water is polar
Ions will be attracted to the opposite charges
Ions will be surrounded by water molecules

Question 24

Why does water have a high latent heat of vaporisation + why is this beneficial

Answer 24

Lots of energy required to break hydrogen bonds
Evaporation of sweat cools down the body.

Question 25

Why does water have a specific heat capacity

Answer 25

Lots of heat used to break hydrogen bonds so less heat to actually increase the temperature

Question 26

Why is it important water has a specific heat capacity

Answer 26

Acts as a buffer prevent temperature changes

Question 27

Cohesion is between

Answer 27

Water molecules

Question 28

Adhesion is between

Answer 28

Water and other molecules

Question 29

Benefits of water cohesion

Answer 29

Supports columns of water in tube - like transport e.g. xylem
Strong surface tension when it meets air