L1 - Water

Question 1

What is cohesion?

Answer 1

a water molecule stuck to other water molecules by hydrogen bonding

Question 2

What is adhesion?

Answer 2

a water molecule stuck to other polar molecules by hydrogen bonding

Question 3

What are the properties of water?

Answer 3

• High surface tension
• High specific heat capacity
• High heat of vaporaton
• Solid water is less dense than liquid water
• Excellent solvent
• Forms ions

Question 4

What type of bond is water?

the single H2O part

Answer 4

a covalent bond

Question 5

What is a high specific heat capacity?

Answer 5

Where a large amount of energy is required to change the temperature of water

Question 6

What is a high heat of vaporization?

Answer 6

Where the evaporation of water from a surface causes cooling of that surface

e.g. evaporation of water / sweating cools the body of many organisms

Question 7

What does Solid water is less dense than liquid water mean?

Answer 7

Bodies of water freeze from the top down

This provides insulation for organisms living under the ice + prevents them being stranded on the surface
Ice provides a habitat for other organisms on top

Question 8

Why is water an excellent solvent?

Answer 8

Because It dissolves polar molecules and charged ions

It also dissolves some small non-polar molecules

Question 9

Why is water important?

3

Answer 9

Is a reactant in cells
(photosynthesis, hydrolysis)

Provides structural support in cells

Keeps organisms cool to maintain an
optimum body temperature

Question 10

What are the contents of a water

molecule?

Answer 10

1 oxygen atom

2 hydrogen atoms

Question 11

What type of molecule is water?

Answer 11

A polarity molecule

Question 12

Water is a polarity molecule

What does this mean?

Answer 12

The oxygen atoms in water are
slightly negatively charged

And

The hydrogen atoms in water are
slightly positively charged

Question 13

What type of bonding does the

polarity make water?

Answer 13

The polarity of water molecules
means that a hydrogen atom on one
water molecule is attracted to the
oxygen atom on another water molecule

This attraction is called hydrogen bonding

Question 14

What type of reactions is water

commonly used for formed in?

Answer 14

Metabolic reactions

Such as condensation and
hydrolysis reactions

Question 15

How is water involved in hydrolysis

reactions?

Answer 15

A bond is broken and a water

molecule is used up

Question 16

How is water involved in

condensation reactions?

Answer 16

A new bond is formed and a water

molecule is released

Question 17

What does cohesion produce?

Answer 17

Surface tension where water meets
air

This is why water forms droplets when placed on
a dry surface rather than being flattened out by
gravity

Plants use this to help transport water from their
roots to their leaves

Question 18

How does the high specific heat

capacity of water compare to sand?

Answer 18

It is much higher for water than sand
which is why land cools faster than
the sea

Question 19

high specific heat capacity
How do warm blooded animals use
water?

Answer 19

To more evenly disperse heat in

Their bodies

Question 20

High heat of vaporisation

Why is a lot of energy needed for water to evaporate?

Answer 20

As liquid water heats up, hydrogen
bonding makes it difficult to
separate the water molecules from
each other meaning a lot of energy is needed for
water to evaporate