paper 1 definitions

Question 1

acid

Answer 1

proton donor

Question 2

activation energy

Answer 2

minimum energy required for a reaction to take place

Question 3

base

Answer 3

proton acceptor

Question 4

coordination number

Answer 4

number of dative covalent (coordinate) bonds attached to the central metal ion

Question 5

dative covalent (coordinate) bonding

Answer 5

shared pair of electrons has been supplied by one of the bonding atoms only

Question 6

disproportionation

Answer 6

oxidation and reduction of the same element

Question 7

electronegativity

Answer 7

the ability of an atom to attract the bonding electrons in a covalent bond

Question 8

enthalpy change of atomisation

Answer 8

formation of 1 mol of gaseous atoms from the elements

Question 9

enthalpy change of combustion

Answer 9

complete combustion of 1 mol of a substance

Question 10

enthalpy change of formation

Answer 10

formation of 1 mol of a compound from its elements

Question 11

enthalpy change of hydration

Answer 11

dissolving of gaseous ions in water to form one mole of aqueous ions

Question 12

enthalpy change of neutralisation

Answer 12

formation of 1 mol of water from neutralisation

Question 13

enthalpy change of solution

Answer 13

one mol of a solute dissolves in a solvent

Question 14

entropy

Answer 14

measure of the dispersal of energy in a system where the greater it is, the more disordered a system

Question 15

first electron affinity

Answer 15

addition of 1 mol of electrons from 1 mol of gaseous atoms to form 1- ions

Question 16

first ionisation energy

Answer 16

removal of 1 mol of electrons for 1 mol of gaseous atoms to form 1+ ions

Question 17

hydrated salt

Answer 17

contains water of crystallisation

Question 18

isotopes

Answer 18

atoms of the same element with different number of neutrons and different masses

Question 19

lattice enthalpy

Answer 19

formation of 1 mol of ionic lattice from gaseous ion

Question 20

ligand

Answer 20

molecule or ion that donates a pair of electrons to a central metal ion

Question 21

lone pair

Answer 21

pair of electrons that are not shared

Question 22

metallic bonding

Answer 22

strong electrostatic attraction between cations and delocalised electrons

Question 23

multiple covalent bonding

Answer 23

shared pair of multiple electrons

Question 24

orbital

Answer 24

a region around the nucleus that can hold up to 2 electrons, with opposite spins

Question 25

oxidising agent

Answer 25

gain of electrons

Question 26

oxidation

Answer 26

loss of electrons and hydrogens and gain of oxygen

Question 27

reducing agent

Answer 27

loss of electrons

Question 28

reduction

Answer 28

gain of electrons and hydrogens and loss of oxygens

Question 29

relative atomic mass

Answer 29

weighted mean mass of an atom of an element relative to 1/12th of the mass of a carbon-12 atom

Question 30

relative isotopic mass

Answer 30

mass of an isotope relative to 1/12th of the mass of a carbon-12 atom

Question 31

single covalent bonding

Answer 31

shared pair of electrons

Question 32

standard electrode (redox) potential

Answer 32

tendency to be reduced and gain electrons

Question 33

stereoisomerism

Answer 33

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

Question 34

transition

Answer 34

d- block elements that form at least 1 ion with a partially filled d-orbital

Question 35

average bond enthalpy

Answer 35

breaking of 1 mol of bonds in gaseous molecules

Question 36

buffer solution

Answer 36

system that minimises pH changes on addition of small amounts of an acid or a base

Question 37

complex ion

Answer 37

a transition metal ion bonded to ligands by dative covalent (coordinate) bonds