Module 3 - Keywords Flashcards
Periodicity
Repeating trends in physical and chemical properties across periods
S Block Element
An element with its highest energy electron in an s orbital
P Block Element
An element with its highest energy electron in a p orbital
D Block Element
An element with its highest energy electron in a d orbital
First Ionisation Energy
Energy required to remove 1 mol of electrons from 1 mol of gaseous atoms to form 1 mol of 1+ ions
Second Ionisation Energy
Energy required to remove 1 mol of electrons from 1 mol of gaseous 1+ ions to form 1 mol of 2+ ions
Successive Ionisation Energies
Energy required to remove each subsequent 1 mol of electrons from 1 mol of gaseous ions
Nuclear Charge
The positive charge found in the nucleus of every atom
Metallic Bonding
Strong electrostatic between cations and delocalised electrons
Giant Covalent Lattices
Networks of atoms bonded by strong covalent bonds
Diatomic
Molecule containing 2 atoms
Disproportionation
Oxidation and reduction of the same element
Bleach
Formed by the reaction of chlorine with cold, dilute aqueous sodium hydroxide
Precipitate
A solid that forms on reactions of solutions
Halide
A compound containing an element from group 17 (halogens)
Exothermic
Where the products have less energy than the reactants. Energy is given out to the surroundings (temp goes up). ∆H, is negative. Bond making
Endothermic
Where the products have more energy than the reactants. Energy is taken in from the surroundings (temperature goes down) . ∆H, is positive. Bond breaking
Activation energy
the minimum energy which must be available to a chemical system with potential reactants to result in a chemical reaction
Standard conditions
100kPa, 298K, concentration of 1.omoldm-3. substances in their standard states
Standard state
the physical state of a substance under standard conditions
(Standard) enthalpy change of reaction
the enthalpy change when the amount in moles of substance as written react (under standard conditions)
(Standard) enthalpy change of combustion
the enthalpy change when 1 mole of substance is combusted/burnt completely, in excess oxygen, (under standard conditions)
(Standard) enthalpy change of formation
the enthalpy change when 1 mole of substance is formed from its elements, (under standard conditions)
(Standard) enthalpy change of neutralisation
the enthalpy change associated with the formation of one mole of water from a neutralisation reaction, (under standard conditions)
Bond enthalpy
the energy required to make/break a covalent bond
Average bond enthalpy
the average enthalpy change that takes place when breaking, by homolytic fission, 1 mole of a given type of bond in the molecules of a gaseous species
Hess’s law
the total energy change for a reaction is the same regardless of the route taken
