Everything chemistry

Question 1

Boiling point:

Answer 1

The temperature at which the vapour pressure equals atmospheric pressure

Question 2

Melting point:

Answer 2

The temperature at which the solid and liquid phases of a substance are at equilibrium

Question 3

Vapour pressure:

Answer 3

The pressure exerted by a vapour at equilibrium with its liquid in a closed system

Question 4

Organic molecules:

Answer 4

molecules containing carbon atoms

Question 5

Functional group:

Answer 5

a bond or an atom or a group of atoms that determine(s) the physical and chemical properties of a group of
organic compounds

Question 6

Hydrocarbon:

Answer 6

organic compounds that consist of hydrogen and carbon only

Question 7

Homologous series:

Answer 7

a series of organic compounds that can be described by the same general formula OR in which one
member differs from the next with a CH2 group

Question 8

Saturated compounds:

Answer 8

compounds in which there are no multiple bonds between C atoms in their hydrocarbon chains

Question 9

Unsaturated compounds:

Answer 9

compounds with one or more multiple bonds between C atoms in their hydrocarbon chains

Question 10

Functional group:

Answer 10

A bond or an atom or a group of atoms that determine(s) the physical and chemical properties of a group of
organic compounds

Question 11

Molecular formula:

Answer 11

a chemical formula that indicates the element and numbers of each of the atoms in a molecule

Question 12

Structural formula:

Answer 12

a structural formula of a compound shows which atoms are attached to which within the molecule. Atoms
are represented by their chemical symbols and lines are used to represent ALL the bonds that hold the atoms together

Question 13

Condensed structural formula:

Answer 13

this notation shows the way in which atoms are bonded together in the molecule, but DOES
NOT SHOW ALL bond lines

Question 14

Structural isomer:

Answer 14

Organic molecules with the same molecular formula, but different structural formulae

Question 15

Macromolecule:

Answer 15

A molecule that consists of a large number of atoms

Question 16

Polymer:

Answer 16

A large molecule composed of smaller monomer units covalently bonded to each other in a repeating pattern

Question 17

Monomer:

Answer 17

Small organic molecules that can be covalently bonded to each other in a repeating pattern

Question 18

Polymerisation:

Answer 18

A chemical reaction in which monomer molecules join to form a polymer

Question 19

Addition polymerisation:

Answer 19

A reaction in which small molecules join to form very large molecules by adding on double bonds

Question 20

Addition polymer:

Answer 20

A polymer formed when monomers (usually containing a double bond) combine through an addition
reaction.

Question 21

Condensation polymerisation:

Answer 21

Molecules of two monomers with different functional groups undergo condensation reactions
with the loss of small molecules, usually water

Question 21

Condensation polymer:

Answer 21

A polymer formed by two monomers with different functional groups that are linked together in a
condensation reaction in which a small molecule, usually water, is lost

Question 22

Heat of reaction (ΔH):

Answer 22

the energy absorbed or released in a chemical reaction

Question 23

Exothermic reactions:

Answer 23

reactions that release energy

Question 24

Endothermic reactions:

Answer 24

reactions that absorb energy

Question 25

Activation energy:

Answer 25

the minimum energy needed for a reaction to take place

Question 26

Activated complex:

Answer 26

the unstable transition state from reactants to products

Question 27

Reaction rate:

Answer 27

as the change in concentration of reactants or products per unit time

Question 28

Positive catalyst:

Answer 28

a substance that increases the rate of a chemical reaction without itself undergoing a permanent change.

Question 29

Open system:

Answer 29

one which continuously interacts with its environment

Question 30

Closed system:

Answer 30

one which is isolated from its surroundings

Question 31

Chemical equilibrium:

Answer 31

it is a dynamic equilibrium when the rate of the forward reaction equals the rate of the reverse reaction

Question 32

Le Chatelier’s principle:

Answer 32

when the equilibrium in a closed system is disturbed, the system will re-instate a new equilibrium by favouring the reaction that will oppose the disturbance

Question 33

Arrhenius theory Acid:

Answer 33

a substance that produces hydrogen ions (H+) when it dissolves in water

Question 34

Arrhenius theory Base:

Answer 34

a substance that produces hydroxide ions (OH–) when it dissolves in water

Question 35

Lowry-Brønsted theory: Acid:

Answer 35

a proton (H+ ion) donor

Question 36

Lowry-Brønsted theory: Base:

Answer 36

a proton (H+ ion) acceptor

Question 37

Strong acids:

Answer 37

ionise completely in water to form a high concentration of H3O+ ions.

Question 38

Weak acids:

Answer 38

ionise incompletely in water to form a low concentration of H3O+ ions.

Question 39

Strong bases:

Answer 39

dissociate completely in water to form a high concentration of OH– ions.

Question 40

Weak bases:

Answer 40

dissociate/ionise incompletely in water to form a low concentration of OH– ions.

Question 41

Concentrated acids/bases:

Answer 41

contain a large amount (number of moles) of acid/base in proportion to the volume of water

Question 42

Dilute acids/bases:

Answer 42

contain a small amount (number of moles) of acid/base in proportion to the volume of water

Question 43

Ampholyte (amphiprotic substance):

Answer 43

a substance that can act as either an acid or a base. Eg. Water

Question 44

Equivalence point (of a titration):

Answer 44

the point at which the acid/base has completely reacted with the base/acid.

Question 45

Endpoint (of a titration):

Answer 45

the point where the indicator changes colour

Question 46

Hydrolysis:

Answer 46

the reaction of a salt with water

Question 47

Auto-ionisation of water:

Answer 47

the reaction of water with itself to form H3O+ ions and OH– ions

Question 48

Kw:

Answer 48

the equilibrium constant for the ionisation of water or the ionic product of water or the ionisation constant of water,

Question 49

Oxidation:

Answer 49

a loss of electrons, an increase in oxidation number

Question 50

Reduction:

Answer 50

a gain of electrons, a decrease in oxidation number

Question 51

Oxidising agent:

Answer 51

a substance that is reduced/gains electrons.

Question 52

Reducing agent:

Answer 52

a substance that is oxidised/loses electrons.

Question 53

Anode:

Answer 53

the electrode where oxidation takes place

Question 54

Cathode:

Answer 54

the electrode where reduction takes place

Question 55

Electrolyte:

Answer 55

a substance of which the aqueous solution contains ions OR a substance that dissolves in water to give a solution that conducts electricity

Question 56

Electrolysis:

Answer 56

the chemical process in which electrical energy is converted to chemical energy OR the use of electrical energy to produce a chemical change

Question 57

Galvanic cell:

Answer 57

a cell in which chemical energy is converted to electrical energy

Question 58

Electrolytic cell:

Answer 58

a cell in which electrical energy is converted into chemical energy