ORGANIC CHEMISTRY

Question 1

Hydrocarbon

Answer 1

a compound that contains only hydrogen and carbon

Question 2

Homologous Series

Answer 2

defines as a series of compounds of uniform chemical type, showing gradations in physical properties, having a general formula for its members, each member having a similar method of preparation, each member differing from the previous by a CH2 unit.

Question 3

Structural isomers

Answer 3

are compounds with the same molecular formula but different structural formulae.

Question 4

Aliphatic compound

Answer 4

an organic compound that consists of open chains of carbon atoms and closed chain compounds (rings) that resemble them in chemical properties.

Question 5

Aromatic compounds

Answer 5

are compounds that contain a benzene ring in their structure.

Question 6

Octane Number of a fuel

Answer 6

is a measure of its tendency to resist knocking.

Question 7

Catalytic Cracking

Answer 7

the breaking down of long-chain hydrocarbon molecules into short chain molecules for which there is greater demand.

Question 8

Heat of Reaction

Answer 8

the heat change when the number of moles of reactants indicated in the balanced equation for the reaction react completely.

Question 9

Heat of Combustion

Answer 9

of a substance is the heat change when one mole of the substance is burned completely in excess oxygen.

Question 10

Kilogram Calorific Value

Answer 10

of a a fuel is the heat energy produced when one kg of the fuel is burned completely in oxygen.

Question 11

Bond energy

Answer 11

the energy required to break one mole of covalent bonds and to separate the neutral atoms completely from each other.

Question 12

Heat of Neutralisation

Answer 12

the heat change when one mole of H+ ions from an acid reacts with one mole of OHions from a base.

Question 13

Hess’s Law

Answer 13

states that if a chemical reaction takes place in a number of stages, the sum of the heat changes in the separate stages is equal to the heat change if the reaction is carried out in one stage.

Question 14

Law of Conservation of Energy

Answer 14

states that energy cannot be created or destroyed, but can only be converted from one form of energy into another.

Question 15

Functional group

Answer 15

is an atom or group of atoms which is responsible for the characteristic properties of a series of organic compounds.

Question 16

Substitution reaction

Answer 16

is a chemical reaction in which an atom or group of atoms in a molecule is replaced by another atom or group of atoms.

Question 17

Mechanism of a reaction

Answer 17

is the detailed step by step description of how the overall reaction occurs.

Question 18

Addition reaction

Answer 18

is one in which two substances react together to form a single substance.

Question 19

Polymers

Answer 19

are long chain molecules made by joining together many small chain molecules.

Question 20

Organic Synthesis

Answer 20

is the process of making organic compounds from simpler starting materials.

Question 21

Chromatography

Answer 21

is a separation technique in which a mobile phase carrying a mixture moves in contact with a selectively adsorbent stationary phase.

Question 22

Reflux

Answer 22

a process in which the reactants are boiled in a container usually a round bottom flask. The vapour that is formed in the boiling process remains in the container (e.g. Round bottom flask) because of the cooking process involving the condenser attached to the round bottom flask. It helps to keeps the product formed in the container without escaping. The product that is in the vapour state returns to it’s liquid form.