Definitions and formulae

Question 1

Addition reaction

Answer 1

A reaction where a molecule joins to an unsaturated molecule to produce a saturated molecule

Question 2

Aliphatic

Answer 2

Organic compounds containing C chains and branches

Question 3

Aromatic

Answer 3

Organic compounds containing one or more benzene ring(s)

Question 4

Carbocation

Answer 4

A positive ion with the positive charge on a C atom

Question 5

What is a benzene ring

Answer 5

Benzene is an important organic chemical compound with the chemical formula C6H6. The benzene molecule is composed of 6 carbon atoms joined in a ring with 1 hydrogen atom attached to each. As it contains only carbon and hydrogen atoms, benzene is classed as a hydrocarbon.

Question 6

Cyclic

Answer 6

Organic compounds containing C rings (not aromatic rings) also called alicyclic

Question 7

Dehydration

Answer 7

Elimination of Water

Question 8

Dehydrogenation

Answer 8

Elimination of hydrogen

Question 9

Electrophile

Answer 9

Lone pair receptor

Question 10

Elimination reaction

Answer 10

Reaction where a molecule is lost from a saturated molecule to an unsaturated molecule

Question 11

Free radical

Answer 11

Species with an unpaired electron

Question 12

Functional group

Answer 12

The atom or group atoms that is responsible for most of the chemical reactions of a molecule

Question 13

Homologous series

Answer 13

A family of compounds with the same general formula and similar chemical property’s. In a series, each member differs by the addition of a CH2 group and there is a gradual change in the physical properties.

Question 14

Hydration

Answer 14

Addition of water

Question 15

Hydrocarbon

Answer 15

Molecule containing hydrogen and carbon only

Question 16

Hydrogenation

Answer 16

Addition of hydrogen

Question 17

Hydrolysis

Answer 17

A reaction involving the breaking down of bonds due to reaction with water

Question 18

Nucleophile

Answer 18

Lone pair donor

Question 19

Organic chemistry

Answer 19

Study of compounds containing carbon

Question 20

Saturated

Answer 20

Molecule containing no double bonds

Question 21

Stereoisomers

Answer 21

Molecules with the same molecular and structural formulae but a different spatial arrangement of atoms

Question 22

Geometric isomers

Answer 22

Type of stereoisomerism: molecules which have a different arrangement of groups around C=C

Question 23

Optical isomers

Answer 23

Type of stereoisomerism: molecules which are non-superimposable mirror images

Question 24

Structural isomers

Answer 24

Molecules with the same molecular formula but different structures

Question 25

Chain isomers

Answer 25

Type of structural isomerism: structural isomers that differ by having a different carbon chain

Question 26

Position isomers

Answer 26

Type of structural isomerism: structural isomers that have differ by having the functional group in a different position

Question 27

Functional group isomers

Answer 27

Type of structural isomerism: structural isomers that differ by having a different functional group

Question 28

Substitution reaction

Answer 28

Reaction where an atom/group replaces another atom/group

Question 29

Unsaturated

Answer 29

Molecule containing double bond(s)

Question 30

Molecular formula

Answer 30

Formula that gives the actual number of atoms of each element in one molecule
E.g butane - C4H10
Or
Ethanol - C2H6O

Question 31

Empirical formula

Answer 31

Formula that gives the simplest ratio of atoms of each element in a compound
E.g. Butane - C2H4
Or
Ethanol - C2H6O

Question 32

General formula

Answer 32

This shows the number of atoms of each element in a substance which has n carbon atoms. All the molecules in a homologous series have the same general formula
E.g. Butane - CnH2n+2
Ethanol - CnH2n+1OH or CnH2n+2O

Question 33

Structural formula

Answer 33

This shows how the atoms are joined together in a molecule
E.g. Butane - CH3CH2CH2CH3
Ethanol - CH3CH2OH

Question 34

Displayed formula

Answer 34

This shows all of the bonds and atoms in a molecule
E.g. H. H. H. H Butane
/. /. /. /
H - C - C - C - C - H
/. /. /. /
H. H. H. H

Question 35

Skeletal formula

Answer 35

This uses lines to represent bonds. Each point represents a C atom. H atoms and bonds to H atoms are not usually shown (unless part of a functional group e.g. Alcohol, aldehyde) other atoms (e.g. O, N, F, Cl, Br, I, S) are shown