AS 2 - Defininitions

Question 0

Empirical formula

Answer 0

Formula which shows the simplest whole number ratio of atoms of each element in a compound

Question 1

Molecular Formula

Answer 1

A formula which shows the actual number of atoms of each element in a molecule

Question 2

Avogadro’s law

Answer 2

Equal volumes of gases, at the same temperature and pressure, contain the same number of particles

Question 3

Molar gas volume

Answer 3

The volume of one molecule of one mole of gas under specified conditions of temperature and pressure

Question 4

Theoretical yield

Answer 4

The maximum possible amount of product from the reactants used

Question 5

What is coal?

Answer 5

Formed from dead plant material

Question 6

What is crude oil and gas?

Answer 6

Formed from dead marine organisms

Question 7

What are hydrocarbons?

Answer 7

Compounds that only contain hydrogen and carbon

Question 8

Catenate

Answer 8

The ability to form multiple covalent bonds

Question 9

What is a homologous series?

Answer 9

Compounds which have the same general formula and have similar chemical properties.

Question 10

What is the functional group?

Answer 10

The part of a structure which determines the characteristic reactions of a compound

Question 11

What is cracking?

Answer 11

Breaking down molecules into smaller ones

Question 12

Structural isomers

Answer 12

Molecules which have the same molecular formula but different structural formula

Question 13

Chain isomers

Answer 13

Similar chemical properties and similar physical properties

Question 14

What is an electrophile?

Answer 14

An ion or molecule that attacks region of high electron density

Question 15

Heterolytic fission

Answer 15

Bond breaking in which the shared electrons go to one atom

Question 16

Homolytic fission

Answer 16

Bond breaking in which one of the shared electrons goes to each atom

Question 17

Free radical

Answer 17

A particle with unpaired electron

Question 18

Monohalogenation

Answer 18

When one hydrogen is replaced with a halogen

Question 19

Primary halogenalkane

Answer 19

Has only one carbon directly attached to the same carbon as the halogen group

Question 20

Secondary halogenalkane

Answer 20

Has two carbons directly attached to the same carbon as the halogen group

Question 21

Tertiary halogenalkane

Answer 21

Has three carbons directly attached to the same carbon as the halogen group

Question 22

Substitution reaction

Answer 22

When one atom of group is replaced with a different atom or group

Question 23

Nucleophile

Answer 23

An ion or molecule, with a lone pair of electrons, that attacks regions of low electron density

Question 24

Hydrolysis

Answer 24

The breaking up of molecules by reaction with water

Question 25

Elimination reaction

Answer 25

A reaction in which a small molecule is removed from a larger molecule

Question 26

Primary alcohol

Answer 26

Only one carbon directly attached to the same carbon as the hydroxyl group

Question 27

Secondary alcohol

Answer 27

Has two carbons directly attached to the same carbon as the hydroxyl group

Question 28

Tertiary alcohol

Answer 28

Has three carbons directly attached to the same carbon as the hydroxyl group

Question 29

Enthalpy

Answer 29

The amount of energy that a substance contains

Question 30

Enthalpy change of a reaction

Answer 30

The difference in energy between products and reactants

Question 31

Endothermic

Answer 31

A reaction in which the enthalpy of the products is greater than the enthalpy of the reactants

Question 32

Exothermic

Answer 32

A reaction in which the enthalpy of the products is less than the enthalpy of the reactants

Question 33

Standard enthalpy of combustion

Answer 33

The enthalpy change when one mole of a substance is completely burnt in oxygen under standard conditions

Question 34

The standard enthalpy of formation

Answer 34

The enthalpy change when one mole of a compound is formed from the elements under standard reaction

Question 35

What is the conservation of energy?

Answer 35

Energy cannot be created or destroyed, it can only be converted from one form to another

Question 36

Hess's Law

Answer 36

The enthalpy change for a reaction is independent of the route taken, provided the initial and final conditions are the same

Question 37

Average bond enthalpy

Answer 37

Energy required to break one mole of a given bond averaged over many compounds

Question 38

Standard enthalpy of neutralisation

Answer 38

The enthalpy change when one mole of water is produced in a neutralisation reaction under standard conditions

Question 39

Standard enthalpy of reaction

Answer 39

Enthalpy change when one mole of a substance is completely reacted under standard conditions

Question 40

Reversible reaction

Answer 40

One which goes in both the forward and backward directions

Question 41

Equilibrium

Answer 41

When a reversible reaction in which the amount of each reactant/product remains constant

Question 42

Dynamic equilibrium

Answer 42

When the rate of forward reaction is equal to the rate of the backward reaction

Question 43

Homogenous

Answer 43

All reactants and products are in the same state