Periodicity Flashcards
What do periods show
Number of the highest energy electron shell in an elements atom
Trend=periodicity
Ionisation energy
The energy required to remove one electron from each atom of an element in one mole of gaseous atoms to form one mole of gaseous 1+ ions
Factors affecting ionisation energy
Atomic radius nuclear charge and electron shielding
Second ionisation energy
The energy required to remove one electron from each atom in one mole of gassiest 1+ ions of an element to form one mole of gassiest 2+ ions
Trends of successive ionisation energy
Always endo BENDO
Increase as more +ve nucleus
Ionisation energy down a group
Atomic radius increases electron shielding increases nuclear attraction decreases first ionisation energy decreases
Ionisation energy trends across a period
Atomic radius Decreases atomic charge increases electron shielding is the same ionisation energy increases
Metallic bonding
The strong electrostatic attraction between cations and delocalised electrons
Properties of metals
Strong metallic bones hi electrical conductivity and high melting and boiling points
Solubility of metals
Ionic bonds too strong to dissolve any interaction will lead to a reaction
Which elements form giant covalent structures
Boron carbon silicon
Solubility of group 2 metals
Increases down group- get more alkaline
Trend of boiling point of halogens
Increases down group as more electrons means stronger London forces and more energy required to break intermolecular forces
Iodine colour in cyclohexane
Violet
Reactivity of halides
Decreases down the group
Trending reactivity of halogens
Down the group atomic radius increases shielding increases less nuclear attraction reactivity decreases
Disproportionation reaction
A redox reaction where the same species is both oxidised and reduced
Activation energy
The energy input required to break bones activation energy is the minimum energy required her reaction to take place
Enthalpy change of reaction
The Enthalpy Change that accompanies a reaction in the mole a quantity shown in a chemical equation under standard conditions with all reactants and products in their standard states
Enthalpy Change of formation
The entropy change that takes place when one mole of a compound is formed from its elements under standard conditions with all reactants and products in their standard states
Enthalpy Change of combustion
Enthalpy Change that takes place when one mole of a substance reacts completely with oxygen under standard conditions with all reactants and products in their standard states
Enthalpy Change of neutralisation
Enthalpy Change that accompanies the reaction of an acid by a base to form one mole of H2O under standard conditions with all reactants and products in the standard state
Always the same
Specific heat capacity
The energy required to raise the temperature of 1 g of a substance by one Kelvin
Issues with accuracy of calculating enthalpy change of combustion
He lost his surroundings incomplete Combustion evaporation of methanol from the wick non-standard conditions
Average bond enthalpy
The energy required to break one mole of a specified type of bond in a gaseous molecule
BENDO
Only average. Different environments have different bond enthalpies
Rate of reaction
Measures how fast are reactant is used up or how fast the product is being formed
Collision Theory
To reacting particles must collide from reaction to occur
They must collide with correct orientation and have sufficient energy to overcome the activation energy
Le Chateliers principle
When a System in equilibrium is subjected to an external change this system readjusts itself to minimise the effect of the change
