Definitions

Question 1

Mole

Answer 1

The amount of substance containing as many particles as there are carbon atoms in exactly 12g of carbon -12

Question 2

Transition Element

Answer 2

A d-block element that forms an ion with an incomplete d-subshell
Transition element atoms lose their 4s electrons first when forming +ions (cations)

Question 3

Atomic Orbital

Answer 3

Is a region within an atom, around the nucleus, that can hold up to two electrons, with opposite spins

Question 4

Acid

Answer 4

A proton (H+) donor

Question 5

Base

Answer 5

A proton (H*) acceptor

Question 6

Atomic Number

Answer 6

Equal to number of protons in nucleus of an atom

Question 7

Mass Number

Answer 7

Equal to the number of protons and neutrons in the nucleus of an atom

Question 8

Isotopes

Answer 8

Atoms of the same element with different numbers of neutrons

Question 9

Relative Atomic Mass(Ar)

Answer 9

The weighted mean mass of an atom of an element compared with 1/12 of the mass of an atom of carbon-12

Question 10

Relative isotopic mass

Answer 10

The mass of an atom of an isotope compared with 1/12 of the mass of an atom of carbon-12

Question 11

Alkali

Answer 11

A base that dissolved in water and releases OH- ions in aqueous solutions

Question 12

Strong and Weak acid

Answer 12

S- completely dissociates into its ions in aqueous solutions

W- partially dissociates into its ions in aqueous solutions

Question 13

Salt

Answer 13

A compound produced when the H+ ion of an acid is replaced by a metal ion or NH4+

Question 14

Successive ionisation energies

Answer 14

Successive ionisation energies are a measure of the energy required to remove each electron in turn

Question 15

First ionisation energy

Answer 15

The energy required to remove one electron from each atom in one mole of gaseous atoms to form one mole of gaseous 1+ ions

Question 16

Homologous series

Answer 16

A family of compounds containing the same functional group but with each successive member of the series differing by a -CH2 group

Question 17

Structural isomerism

Answer 17

Moles with the same molecular formula but different structural formulae

Question 18

Hydrocarbon

Answer 18

A compound that contains ONLY hydrogen and carbon atoms

Question 19

Functional group

Answer 19

An atom/group responsible for the characteristic reactions of the compound

Question 20

Aromatic compounds

Answer 20

Compounds containing a benzene ring

Question 21

Aliphatic compounds

Answer 21

Compounds of carbon and hydrogen joined together in straight chains, branched chains or non-aromatic rings

Question 22

Homolytic Fission

Answer 22

The breaking of a covalent bond where one electron from the bonding pair goes to each atom to form two radicals

Question 23

Heterolytic fission

Answer 23

The breaking of a covalent bond where one bonding atom receives both electrons from the bonding pairs to form two ions with opposite charges

Question 24

Alicyclic compounds

Answer 24

Arranged in non-aromatic rings with or without side chains

Question 25

Exothermic reaction

Answer 25

a reaction where heat energy is released to the surroundings. The enthalpy change for the an exothermic reaction has a negative(-) sign Bond forming gives out energy=exo

Question 26

endothermic reaction

Answer 26

A reaction where heat energy is absorbed from the surroundings the enthalpy change when an endothermic reaction has a positive(+) sign Bond breaking requires energy= endo

Question 27

stereoisomers

Answer 27

compounds with the same structural formula but with a different arrangement of the atoms in space

Question 28

electrophile

Answer 28

Electrophile is an electron pair acceptor

Question 29

curly arrow

Answer 29

Arrow shows the movement of an electron pair to either break or make covalent bond

Question 30

enthalpy change of neutralisation

Answer 30

enthalpy change that accompanies the formation of one mole of H2O from neutralisation under standard conditions

Question 31

enthalpy change of formation

Answer 31

enthalpy change when one mole of a compound is formed from its elements under standard conditions

Question 32

enthalpy change of combustion

Answer 32

enthalpy change for the complete combustion of one mole of a substance under standard conditions

Question 33

Average bond enthalpy

Answer 33

The average enthalpy change for the breaking of one mole of bonds in gaseous molecules by homolytic fission

Question 34

Dehydration of an alcohol

Answer 34

a reaction where a H2O molecule is removed from a saturated molecule to form an unsaturated molecule

Question 35

Nucleophilic Substitution

Answer 35

CH3CH2OH + NaBr + H2SO4 ->CH3CH2Br NaHSO4 + H2O conditions: heat under reflux

Question 36

nucleophile

Answer 36

electron pair donor