Definitions + Rukes Flashcards
Electron orbital
Region of space in which an electron spends most of its time
Aufbau principle
Electrons fill the lowest available energy level
Hund’s rule
Electrons remain impaired in every sub shell as far as possible
1st ionisation energy
Energy required to remove 1 electron from each atom in 1 mole of gaseous atoms producing 1 mole of gaseous ions
Linear bond angle
180
Tetrahedral bond angle
109.5
Trigonal planar bond angle
120
Pyramidal bond angle
107
Bent bond angle
104.5
Octahedral bond angle
90
Electronegativity
The power of an atom to attract the electrons in a covalent bond
Physical properties of halogens at room temperature
Fluorine- pale yellow gas
Chlorine- pale green gas
Bromine- dark red liquid
Iodine- shiny black crystals
KCl + Br2
Orange upper layer
Yellow lower layer
KCl and +I2
Purple upper layer
Orange lower level
KBr + Cl2
Orange upper level
Yellow lower level
KBr+ I2
Purple upper layer
Orange lower layer
KI+ Cl2
Purple upper layer
Orange lower layer
Br2+ KI
Purple upper layer
Orange lower layer
Order of ion tests
Carbonates
Sulfates
Halides
Ammonia?
Carbonate test
Dilute HNO3
Fizzing
Sulfates test
Excess barium ions eg BaCl2
White precipitate
Halide tests
Add acidified silver nitrate
Then check with dilute and conc ammonia
Ammonia test
Add dilute NaOH
When warmed moist ph paper will turn blue
Standard enthalpy formation
1 mole of substance is formed from its elements in their standard states
Enthalpy of combustion
Enthalpy when 1 mole of substance is completely burned in oxygen under standard conditions
Enthalpy of reaction
Enthalpy when molar quantities as stated in the chemical equation react together under standard conditions
Enthalpy of neutralisation
Enthalpy when and acid and a base react together in their standard stated to form 1 mole H2O under standard conditions
Bond enthalpy
The average energy required to break 1 mole of bonds in gaseous molecules
Hess’s law
Enthalpy change is independent of the path taken provided initial and final conditions are the same
Homogeneous catalyst
Reactants and catalyst in the same state
Heterogeneous catalyst
Reactants and catalyst in different states
Standard lattice enthalpy
Enthalpy change when 1 mole of an ionic compound is formed from its gaseous ions under standard conditions
Enthalpy of atomisation
Enthalpy change when 1 mole of gaseous atoms is formed from the element in its standard state
1st electron affinity
Enthalpy change when 1 electron is added to each atom in 1 mole of gaseous atoms to form 1 mole of gaseous 1- ions
Enthalpy hydration
Enthalpy change when a solutions of ions is made from 1 mole of gaseous ions
Enthalpy of solution
Enthalpy change when 1 mole of a solute dissolves to form an infinitely dilute solution
Spontaneous reaction
No extra energy is need to continue the reaction
