water

Question 1

What partial charge does oxygen have?

Answer 1

Electronegative (electrons are closer to the oxygen which carry a negative charge)

Question 2

Does water (a polar molecule) dissolve polar or non polar molecules?

Answer 2

Polar (has a partial charge)

Question 3

Why is water liquid at room temperature 0-100

Answer 3

Because there isn’t enough energy to overcome the many hydrogen bonds, but enough that they keep breaking and reforming and not in a fixed giant lattice structure that ice is in

Question 4

Are hydrogen bonds strong or weak

Answer 4

Weak but as there are many of them, large amounts of energy is needed to break them

Question 5

Cohesion is when water molecules attract to

Answer 5

Each other

Question 6

Adhesion is when water molecules attach to

Answer 6

Other molecules

Question 7

Cohesion and adhesion assist in

Answer 7

Transpiration through the xylem

Question 8

Why is water thermostable habitat for a biodiverse aquatic life?

Answer 8

It has high specific heat capacity - Large amount of thermal energy is needed to change the temperature by breaking hydrogen bonds

Question 9

How is water used for thermoregulation in the body?

Answer 9

It has high latent heat of vaporisation - large amounts of thermal energy is needed to break hydrogen bonds and change state so heat energy is used up when evaporating sweat which cools down the skins surface

Question 10

Why is water a good transport medium?

Answer 10

Water is a universal solvent - polar molecules can be dissolved because the charges are attracted to the opposite charged region of the water molecules

Question 11

How does ice float and what is the benefit of it?

Answer 11

Water is less dense at solid state as hydrogen bonds are fixed - Creating a habitat for polar bears and an insulating layer underneath allowing a thermostable environment for fish that polar bears can eat

Question 12

What allows water to become a habitat for water Bowman

Answer 12

It has high surface tension

Question 13

What uses does water have due to its incompressibility?

Answer 13

It is the hydrostatic skeleton of a jellyfish which loses its shape out of water
It holds the structure of the eyes
It keeps plants turgid
It Creates buoyancy for big animals like the blue whales so they float

Question 14

What is the benefit of water being transparent?

Answer 14

It allows light to be reflected to the retina for sight
Water can be reflected to the bottom of the ocean for underwater photosynthesis

Question 15

Water has low viscosity (resistance to flow) so it is a great transport medium. why is this good?

Answer 15

A transfers nutrients in the bloodstream

Question 16

What does delta mean and when is it used

Answer 16

It means partial and it used to describe the partially negatively charged oxygen and the partially positively charged hydrogen in water

Question 17

What causes adhesion and cohesion?

Answer 17

The hydrogen bonds between water molecules

Question 18

What is a hydrogen bond?

Answer 18

A weak bond between a slightly positively charged hydrogen atom in one molecule and a slightly negatively charged atom in another molecule

Question 19

Why does water have high specific heat capacity?

Answer 19

When water is heated, a lot of energy is absorbed by the hydrogen bonds between water molecules so it takes a lot of energy to increase the temperature and break hydrogen many bonds

Question 20

Why is water used to cool things down?

Answer 20

It has high latent heat of evaporation which means use up a lot of heat energy to evaporate from a surface cooling the surface down which helps lower the temperature

Question 21

Why does the polarity of water make it a good transport medium?

Answer 21

It makes water very cohesive and a good solvent

Question 22

Why is the structure of ice like this

Answer 22

Because the water molecules are being held further apart by fixed hydrogen bonds and they have formed a lattice shape

Question 23

How is the formation of ice beneficial for organisms?

Answer 23

In cold temperatures, ice forms and insulating lay on top of water. This means the organisms that live in the water below don’t freeze and can still move around.

Question 24

Describe how an Mg2+ ions dissolve in water

Answer 24

The slightly negatively charged end of the water molecules will be attracted to the positive ion meaning the positive iron will get surrounded by water molecules

Question 25

Why do kangaroos lick saliva onto their forearms in hot weather?

Answer 25

A lot of energy is removed from the kangaroo body when the water in the saliva evaporates from the kangaroos body as water has high latent heat of evaporation, this reduces the kangaroo body temperature

Question 26

Why do trees stay cool even in hot weather?

Answer 26

Water has ghigh specific heat capacity which means it takes a lot of energy to break the hydrogen bonds in water to heat up which means it doesn’t heat up as quickly as air

Question 27

How does water flow up a tree to leaves?

Answer 27

The water molecules are polar which means the hydrogen bonds form between them making them cohesive which allows them to travel up the tree trunk