December Mock Definitions

Question 1

Isotope

Answer 1

as atoms of the same element with different numbers of neutrons and different masses

Question 2

Relative isotopic mass

Answer 2

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

Question 3

Relative atomic mass

Answer 3

Weighted mean mass of an atom compared with 1/12th the mass of carbon-12

Question 4

Homologous series

Answer 4

a series of organic compounds having the same functional group but with each successive member differing by CH2

Question 5

Structural isomers

Answer 5

compounds with the same molecular

formula but different structural formulae

Question 6

Radical

Answer 6

A species with an unpaired electron

Question 7

Stereoisomers

Answer 7

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

Question 8

E/Z isomerism

Answer 8

an example of stereoisomerism, in terms of restricted rotation about a double bond and the requirement for two different groups to be attached to each carbon atom of the C=C group

Question 9

Cis-trans isomerism

Answer 9

a special case

of E/Z isomerism in which two of the substituent groups attached to each carbon atom of the C=C group are the same

Question 10

Electrophile

Answer 10

Electron pair acceptor

Question 11

Nucleophile

Answer 11

Electron pair donor

Question 12

Optical isomerism

Answer 12

an example of stereoisomerism, in terms of non- superimposable mirror images about a chiral centre

Question 13

Amount of substance

Answer 13

a quantity with the unit mole

Question 14

mole

Answer 14

the amount of any substance containing as many elementary particles as there are carbon atoms in exactly 12g of the carbon-12 isotope

Question 15

Avogadro’s constant

Answer 15

the number of

partcles per mole, 6.02 × 10 ^23 mol–1

Question 16

molar mass

Answer 16

mass per mole in g mol ^-1

Question 17

molar gas volume

Answer 17

gas volume per mole in dm^3 mol^-1

Question 18

anhydrous

Answer 18

containing no water molecules

Question 19

hydrated

Answer 19

a crystalline compound containgin water molecules

Question 20

water of crystallisation

Answer 20

water molecules that are bonded into the crystalline structure of a compound

Question 21

what are acids and alkalis

Answer 21

acids - release H+ in aqeous solution

alkalies - release OH- in aqeous solution

Question 22

aromic orbital

Answer 22

a region around the nucleus that can hold

up to two electrons, with opposite spins

Question 23

ionic bonding

Answer 23

electrostatc atracton between

positve and negatve ions

Question 24

covalent bond

Answer 24

strong electrostatc
atracton between a shared pair of electrons and
the nuclei of the bonded atoms

Question 25

average bond enthalpy

Answer 25

average enthalpy change that takes place when one mole of gaseous bonds are broken

Question 26

aliphatic

not a definition but need to know

Answer 26

a compound containing carbon
and hydrogen joined together in straight
chains, branched chains or non-aromatc
rings

Question 27

alicyclic

not a definition but need to know

Answer 27

an aliphatc compound arranged
in non-aromatc rings with or without side
chains

Question 28

aromatic

not a definition but need to know

Answer 28

a compound containing a

benzene ring

Question 29

homolytic fission

Answer 29

in terms of each bonding
atom receiving one electron from the
bonded pair, forming two radicals

Question 30

heterolytic fission

Answer 30

in terms of one bonding
atom receiving both electrons from the
bonded pair