Water

Question 1

Solvent - Definition.

Answer 1

A liquid substance which can dissolve a wide range of molecules.

Question 2

Specific Heat Capacity - Definition.

Answer 2

The amount of heat that is required to create a rise in 1kg (of water) by 1*C.

Question 3

Latent Heat of Vaporisation - Definition.

Answer 3

The amount of heat needed to turn a substance into a gas.

Question 4

Density - Definition.

Answer 4

A measure of mass per unit volume.

Question 5

Adhesion - Definition.

Answer 5

The tendency of molecules to be attracted to other molecules of a different type.

Question 6

Cohesion - Definition.

Answer 6

The tendency of molecules of a substance to attract to one another.

Question 7

Capillarity - Definition.

Answer 7

The result of intermolecular forces between various molecules.

Question 8

Surface Tension - Definition.

Answer 8

The uneven distribution of force at a boundary interface caused by molecular bonding.

Question 9

Liquid - Definition.

Answer 9

A state of matter in which all the particles are free to move.

Question 10

Molecular Mobility - Definition.

Answer 10

The ability of a molecule to move freely in a substance.

Question 11

Transparent - Definition.

Answer 11

The ability for light to penetrate a substance fully.

Question 12

Viscosity - Definition.

Answer 12

A fluid’s resistance to flow.

Question 13

Compression - Definition.

Answer 13

The ability for particles to be squashed to decrease their volume.

Question 14

Polarity - Definition.

Answer 14

Uneven distribution of charges in a molecule.

Question 15

Hydrogen Bond - Definition.

Answer 15

A chemical bond formed between the positive charge on a hydrogen atom and the negative charge on another atom of an adjacent molecule.

Question 16

Amphoteric - Definition.

Answer 16

The ability of a molecule to function as either an acid or a base.

Question 17

Solvent - Biological Importance.

Answer 17

Allows water to act as a transport medium for polar molecules, causing them to dissociate.
It also allows for removal of metabolic wastes such as urea and ammonia.

Question 18

Specific Heat Capacity - Biological Importance.

Answer 18

Lots of energy is required to raise the temp of water, (it has a high specific heat capacity), meaning it acts as a temperature buffer in cells to stop denaturation due to temp changes.

Question 19

Latent Heat of Vaporisation - Biological Importance.

Answer 19

Water within cells and aquatic habitats is slow to freeze and therefore provides a more stable environment.

Question 20

Density - Biological Importance.

Answer 20

Helps nutrient cycling in aquatic environments.

Question 21

Adhesion - Biological Importance.

Answer 21

A strong force of attraction between water molecules and xylem walls allow transpiration to occur.

Question 22

Which property causes “water to be wet”?

Answer 22

Adhesion.

Question 23

Cohesion - Biological Importance.

Answer 23

Molecules are pulled inwards causing them to move up the xylem tissue during transpiration.

Question 24

Capillarity - Biological Importance.

Answer 24

The result of intermolecular forces between various molecules.

Question 25

Surface Tension - Biological Importance.

Answer 25

The surface of water forms a skin which is strong enough to support small aquatic animals.

Question 26

Liquid - Biological Importance.

Answer 26

It remains a liquid over a wide temperature range which allows for stability in metabolic reactions and biological processes.

Question 27

Molecular Mobility - Biological Importance.

Answer 27

Water molecules can easily move in osmosis.

Question 28

Transparent - Biological Importance.

Answer 28

Allows aquatic plants to photosynthesise.

Question 29

Viscosity - Biological Importance.

Answer 29

Enables water to flow easily through tubes such as the xylem and capillaries.

Question 30

Compression - Biological Importance.

Answer 30

Makes water a great support medium for many things such as the general support of large aquatic animals.

Question 31

Amphoteric - Biological Importance.

Answer 31

Water can act as a pH buffer to maintain enzyme reaction are carried out at an optimum pH.

Question 32

Formula of water?

Answer 32

H20

Question 33

Air can easily compress in a syringe, explain what happens to water:

Answer 33

The water will not compress and maintains its volume.

Question 34

Why is it so hard to change the temperature of a large body of water?

Answer 34

The high specific heat capacity means it requires great amounts of energy.

Question 35

Is water a polar or non-polar molecule?

Answer 35

Polar.

Question 36

Where are the polar charges on a water molecule?

Answer 36

There is a small - charge on the Oxygen and a small + charge surrounding the Hydrogens.

Question 37

What type of reaction is water required for?

Answer 37

Hydrolysis.

Question 38

What type of reaction releases water?

Answer 38

Condensation.

Question 39

Is water electronegative?

Answer 39

Yes, water is strongly electronegative.

Question 40

Water is a metabolite, what does this mean?

Answer 40

Hydrolysis reactions require a water molecule and condensation reactions release a water molecule.

Question 41

Explain the structure of a water molecule?

Answer 41

One atom of O and two atoms of H joined together by shared electrons, the shared negative hydrogen electrons are pulled towards the oxygen atoms and are left with a slight negative charge.

Question 42

Two molecules of water are held together how?

Answer 42

Through hydrogen bonds, the slightly negatively-charged oxygen atoms attract the slightly positively-charged hydrogen atoms of the other molecules.

Question 43

Water is very cohesive, what does this aid?

Answer 43

Aids water transport in plants up the xylem and transport in other organisms.

Question 44

How is water used as a metabolite in the formation of proteins?

Answer 44

Amino acids are joined together to make polypeptides by condensation reactions.

Question 45

How is water used as a metabolite in the release of energy?

Answer 45

Energy from ATP is released through a hydrolysis reaction which requires a water molecule.

Question 46

How can water act as a buffer to changes in temperature?

Answer 46

The hydrogen bonds between water molecules can absorb a lot of energy (high specific heat capacity).

Question 47

Why is water acting as a buffer a benefit for organisms?

Answer 47

It helps them to maintain a constant, stable internal body temperature.

Question 48

Why is water known as polar?

Answer 48

There is a positive and negative end of the molecule.

Question 49

Which property of water allows it to be such a successful solvent?

Answer 49

Its polarity.

Question 50

Why does sweat form 'droplets'?

Answer 50

Because of the strong cohesion between H2O molecules.

Question 51

Why can 'pond skaters', and some other insects "walk" on water?

Answer 51

Due to the strong cohesion of water molecules.

Question 52

Which property of water allows it to have a strong cohesion?

Answer 52

Polarity.