Introduction to Organic Chemistry

Question 1

Definition of Aliphatic Hydrocarbon

Answer 1

Open chains of Carbon atoms

Question 2

Definition of Alicyclic Hydrocarbon

Answer 2

Closed rings of Carbon atoms

Question 3

Definition of Aromatic Hydrocarbon

Answer 3

Hydrocarbon containing a benzene ring

Question 4

Functional group

Answer 4

A group within an organic compound responsible for its characteristic chemical properties

Question 5

Homologous Series

Answer 5

A family of compounds containing the same functional group

Question 6

Empirical formula

Answer 6

Shows the simplest ratio of different type of atoms in a molecule

Question 7

Molecular formula

Answer 7

Shows the actual number of each type of atom in a molecule

Question 8

Condensed structural formula

Answer 8

Shows how groups of atoms are arranged sequentially

Question 9

Displayed/Full structural formula

Answer 9

Shows all bonding in a molecule

Question 10

Stereochemical structure

Answer 10

Shows spatial structure of a molecule

Question 11

Skeletal formula

Answer 11

Shows the carbon skeleton with any functional group

Question 12

Homolytic Fission

Answer 12

The breaking of a covalent bond such that one electron goes to each of the atom, forming of free radicals

Question 13

Heterolytic Fission

Answer 13

The breaking of a covalent bond such that the bonding electrons goes to the same atom, forming positive and negative ions.

Question 14

Degree of substitution

Answer 14

Determined by the number of alkyl or aryl groups bonded to it

Question 15

Electrophile

Answer 15

Electron pair acceptor: Electron deficient species and are attracted to regions of negative charge/electron rich sites

Question 16

Nucleophile

Answer 16

Electron pair donor: Electron rich species, which possess at least one lone pair of electrons and are attracted to regions of positive charge/electron deficient sites

Question 17

Free radical

Answer 17

Electrically neutral and contains an unpaired electron formed from homolytic fission

Question 18

Electronic effect

Answer 18

Due to donation/withdrawal of electron through sigma bonds due to the electronegativity difference between atoms.

Delocalization of lone pair of electron into the pi electron cloud of benzene OR Delocalization of pi electron cloud onto the substituent

Question 19

Steric hindrance

Answer 19

Occurs when a substituent hinders an approach of an attacking reactant and either prevents a reaction/lowers reactivity of a particular site of the molecule

Question 20

Isomerism

Answer 20

Existence of two or more compounds with the same molecular formula but different arrangement of atoms.

Question 21

Constitutional/Structural Isomerism

Answer 21

Molecules with the same molecular formula but different structural formula

Question 22

Stereoisomerism

Answer 22

Existence of two or more compounds with the same molecular formula and structural formula but different spatial (3D) arrangement of atoms

Question 23

Cis-Trans Isomerism

Answer 23

In order to exist:
1. Restricted rotation about a double bond/ a ring structure
2. For an alkene, each carbon atom in double bond must have two different groups attached to it.
3. For a cyclic compound, two or more of the carbon atoms in the ring have two different groups attached.

Question 24

Enantiomers

Answer 24

Compounds with the same molecular and structural formula but with different spatial arrangement of atoms

1. It form an non-superimposable mirror image
2. It does not have a plane of symmetry
3. It contains one or more chiral centers

Question 25

Chiral carbon

Answer 25

It is a SP3 hybridised carbon atom and has four different groups attached to it.

Question 26

Meso compound

Answer 26

Molecules which are superimposable on their mirror images. Contains a plane of symmetry.