Giant Structure Flashcards
Name 3 methods of proving ion existence
Electrolysis
Ion migration
X-ray crystallography
How does electrolysis prove ion existence
aq/l
Conduct electricity
Free delocalised electrons to carry charge
How does ion migration prove ion existence
aq coloured ions
Copper chromate solution soaked paper
Crocodile clips, DC power supply
Blue copper cations, yellow chromate anions
How does X-ray crystallography prove ion existence
Diffract through slag crystal
Electron density map
Contours link equal charge regions
Separate ionic solid entities
Lattice energy
Energy change to make 1 mole of a solid ionic crystal from its gaseous ions
Exo
Standard enthalpy change of formation
Energy change to make 1 mole of a compound from it’s elements in their standard state under standard conditions
Standard enthalpy change of atomisation
Energy change to make 1 mole of gaseous atoms from it’s elements in their standard state under standard conditions
Endo
Ionisation energy
Energy to remove 1 electron from each atom/ion in 1 mole of gaseous atoms/ions
Endo
Electron affinity
Energy change to add 1 electron to each atom/ion in 1 mole of gaseous atoms/ions
Describe the energetics pattern of electron affinity
From neutral = exo
From negative = endo
Negative charge of ion and negative charge of electron repel each other, energy must be absorbed to overcome the ESR
Describe the 3 general layers of a borne haber cycle
Natural elements
Gaseous ions
Solid lattice
Describe the differences (4) between a BHC of NaCl and MgCl2
Higher IEs
Higher No.IEs
Higher lattice enthalpy
Double Cl values
Name 3 factors that effect LE
Charge of ions
Size of ions
No. Ions
BHC exam technique terminology
X larger/smaller
More Endo/exo
State what is
How does charge effect LE
Higher charge
Higher ESA between ions
Higher ETO
More exo LE
How does ion size effect LE
Larger size
Ions further away
Less ESA
Less exo LE