Chem- A2 Inorganic & Physical definitions

Question 1

Redox

Answer 1

A reaction in which both oxidation and reduction take place

Question 2

Oxidation number

Answer 2

A measure of the number of electrons that an atom uses to bond with atoms of a different element

Question 3

Oxidising agent

Answer 3

A reagent that oxidises (takes electrons from) another species

Question 4

Reducing agent

Answer 4

A reagent that reduces (adds electrons to) another species

Question 5

Standard electrode potential

Answer 5

The e.m.f of a half cell compared with a standard hydrogen half cell, measured at 298K with all solution concentrations of 1 mol dm^-3 and a gas pressure of 100kPa (1 atm)

Question 6

Fuel cell

Answer 6

Uses the energy from the reaction of a fuel with oxygen to create a voltage

Question 7

d-block elements

Answer 7

The highest energy sub-shell is a d sub-shell

Question 8

Transition elements

Answer 8

d block elements that have an ion with an incomplete d sub-shell

Question 9

Ligand

Answer 9

A molecule or ion that can donate a pair of electrons to a transition metal ion to form a coordinate bond

Question 10

Complex ion

Answer 10

A transition metal ion bonded to one or more ligands by coordinate bonds

Question 11

Coordinate bond

Answer 11

A shared pair of electrons in which one of the bonded atoms provides both the electrons for the shared pair

Question 12

Coordination number

Answer 12

The total number of coordinate bonds formed between a central metal ion and its ligands

Question 13

Bidentate ligand

Answer 13

A ligand which can donate two lone pairs of electrons to a metal ion from two separate atoms to form two coordinate bonds

Question 14

Ligand substitution

Answer 14

A reaction in which one ligand in a complex ion is replaced by another ligand

Question 15

Stereoisomers

Answer 15

Species with the same structural formula but with different arrangements of atoms in space

Question 16

Optical isomers

Answer 16

Stereoisomers that are a pair of non-superimposable mirror images of each other

Question 17

le Chatelier’s

Answer 17

When a system in dynamic equilibrium is subjected to change, the equilibrium position will shift to minimise the change

Question 18

Acid

Answer 18

proton donor

Question 19

Base

Answer 19

proton acceptor

Question 20

Conjugate acid-base pairs

Answer 20

A pair of two species that transform into each other by gain or loss of a proton

Question 21

Strong acid

Answer 21

A proton donor that completely dissociates in solution

Question 22

Weak acid

Answer 22

A proton donor that partially dissociates in solution

Question 23

Acid dissociation constant

Answer 23

Shows the extent of acid dissociation and is defined as: Ka= ([H+][A-]) ÷ [HA]
for acid HA: HA(aq) <=> H+(aq) + A-(aq)

Question 24

pH

Answer 24

pH= -log[H+]

Question 25

Ionic product of water, Kw

Answer 25

Kw= [H+][OH-] (at 25C, Kw= 1.00x10^-14 mol^2 dm^-6)

Question 26

Buffer solution

Answer 26

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

Question 27

Lattice enthalpy

Answer 27

The enthalpy change that accompanies the formation of one mole of an ionic compound from its gaseous ions under standard conditions

Question 28

Enthalpy change of solution

Answer 28

The enthalpy change that takes place when one mole of a compound is completely dissolved in water under standard conditions

Question 29

Enthalpy change of hydration

Answer 29

The enthalpy change that takes place when one mole of isolated gaseous ions is dissolved in water forming one mole of aqueous ions under standard conditions

Question 30

Enthalpy change of formation

Answer 30

The enthalpy change that takes place when one mole of a compound is formed from its constituent elements in their standard states, under standard conditions

Question 31

First ionisation energy

Answer 31

The enthalpy change accompanying the removal of one electron from each atom in one mole of gaseous atoms to form one mole of gaseous 1+ ions

Question 32

Second ionisation energy

Answer 32

The enthalpy change accompanying the removal of one electron from each ion in one mole of gaseous 1+ ions to form one mole of gaseous 2+ ions

Question 33

Enthalpy change of atomisation

Answer 33

The enthalpy change that takes place when one mole of gaseous atoms forms from the element in its standard state

Question 34

First electron affinity

Answer 34

The enthalpy change accompanying the addition of one electron to each atom in one mole of gaseous atoms to form one mole of gaseous 1- ions

Question 35

Second electron affinity

Answer 35

The enthalpy change accompanying the addition of one electron to each ion in one mole of gaseous 1- ions to form one mole of gaseous 2- ions

Question 36

Entropy, S

Answer 36

The quantitative measure of the degree of ‘disorder’ in a system

Question 37

Free energy change, ΔG

Answer 37

The balance between entropy, enthalpy, and temperature for a process: ΔG= ΔH -TΔS
A process can take place spontaneously when ΔG<0 (when ΔG is negative)

Question 38

Rate of reaction

Answer 38

The change in concentration of a reaactant or product per unit time

Question 39

Order, m

Answer 39

The order with respect to a reactant is the power to which the concentration of the reactant is raised in the rate equation

Question 40

Rate constant, k

Answer 40

The constant that links the rate of reaction with the concentrations of the reactants raised to the powers of their orders in the rate equation

Question 41

Rate equation (general)

Answer 41

for A +B -> products: rate= k[A]^m [B]^n

Question 42

Half-life

Answer 42

The time taken for the concentration of a reactant to be reduced by half

Question 43

Rate determining step

Answer 43

The slowest step in the reaction mechanism of a multi-step reaction