A1.1 WATER

Question 1

solvent

Answer 1

The medium into which solutes will dissolve through solvation.

Question 2

solute

Answer 2

the minor component in a solution, dissolved in the solvent

Question 3

solution

Answer 3

a liquid containing a dissolved substance. eg sugar in water

Question 4

hydrogen bonding

Answer 4

A weak intermolecular force that exists when electronegativity creates a polar covalent bond.

Question 5

cation

Answer 5

positive ion

lost electrons

Question 6

anion

Answer 6

negative ion

Question 7

electron

Answer 7

negative charge

Question 8

neutron

Answer 8

neutral charge

Question 9

proton

Answer 9

positive charge

Question 10

adhesion

Answer 10

The force of attraction between water and another material or substance. such as water and glass

Question 11

cohesion

Answer 11

the force of attraction between molecules of the same substance. intra molecular attraction

example - water transferring through a tissue through cohesion (and adhesion)

Question 12

covalent

Answer 12

A chemical bond between two atoms formed by sharing electrons.

Question 13

polarity

Answer 13

the negative and positive charges of a molecule

Question 14

surface tension

Answer 14

The property of a liquid to resist an external force due to the cohesion between their molecules.

Question 15

capillary action

Answer 15

The ability of a liquid to move through narrow tubes that results from cohesion, adhesion and surface tension.

Question 16

water the medium of life

Answer 16

• water in a universal solvent
• water is a metabolite
• water is a temp buffer
• water maintains biological structure

Question 17

atom

Answer 17

smallest unit of matter that makes up everything

Question 18

ions

Answer 18

charge carrying atom or molecule

Question 19

Hydrophilic substances

Answer 19

Substances that freely associate and readily dissolve in water

Question 20

Hydrophobic substances

Answer 20

Substances that do not freely associate or dissolve in water

Question 21

water is a solvent

Answer 21

water as a solvent helps multicellure organisms transport molecules around a body and acts as the medium in which chemical reactions of life occur

Question 22

water is a metabolite

Answer 22

chemical reactions take place in cells
water is a metabolite in many reactions either as a reactant either as a reactant or as a product of reaction
eg. photosynthesis or digestion

Question 23

water is a temperature buffer

Answer 23

many metabolic reaction in cells are catalysed by enzymes
enzyme activity is sensitive to temperature and reactions only occur in a narrow range of temperature
water helps to buffer temperature changes in cells because of its relatively high specific heat capacity

Question 24

water maintains biological structures

Answer 24

water contributes to the formation of cell membranes
water impacts the folding of proteins
water surround DNA to support the double helix

Question 25

Solvent properties of water

Answer 25

medium for metabolism and for transport in plants and animals

hydrophilic molecules dissolve in water

most enzymes catalyse reactions in aqueous solution.

Functions of some molecules in cells depend on them being hydrophobic and insoluble

Question 26

Physical properties of water list

Answer 26

buoyancy, viscosity, thermal conductivity and specific heat capacity

Question 27

Gavia arctica (black throated loon)

Answer 27

Breeds in vicinity of deep freshwater lakes throughout northern Europe, west coast of Alaska and Asia
Catches prey underwater
feathers waxy to trap air and warm them
hollow bone with struts to reduce density

Question 28

Pusa hispida (ringed seal)

Answer 28

Live in Arctic and sub arctic regions of North Pole
Live on ice or under the sea
Less than 1.5 m in length
Distinct pattern of dark spots surrounded by grey rings
blubber to insulate them and keep them warm

Question 29

physical property

Answer 29

measurable behaviour or characteristic of matter that exists without the matter reacting or interacting with other things

Question 30

buoyancy

Answer 30

an upward force applied to an object that is immersed in a fluid
if the buoyant force of the fluid is greater than the objects weigh, the object will float

Question 31

viscosity

Answer 31

is a measure of a fluids tendency to flow
due to the amount of friction the molecules of a liquid experience as they flow over each other
water more viscous than air

Question 32

thermal conductivity

Answer 32

a measure of a materials ability to move hear across a temperature gradient
- determined by how easily energy transfers through the material

Question 33

specific heat capacity

Answer 33

quantity of heat needed to raise the temperature of a chemical per unit mass
water has the highest shc of any liquid

Question 34

how are atoms able to form bonds

Answer 34

electrons may be transferred to other nearby atoms or shared between atoms

Question 35

what is the purpose of bonds

Answer 35

they enable the formation of chemical compounds

Question 36

what are the different types of bonds

Answer 36

• non polar covalent bonds
• polar covalent bond
• ionic bond
• hydrogen bond

Question 37

what are non polar covalent bonds

Answer 37

they share electrons equally

Question 38

what are polar covalent bonds

Answer 38

they share electrons unequally

Question 39

what happens when one atom has more mass than the other atom in the bond

Answer 39

the electrons that are being shared will be pulled towards the heavier atom and one side will be slightly positive and one side will be slightly negative

Question 40

ionic bond

Answer 40

an attraction between a positively charged ion and a negatively charged ion