Periodic Classification of Elements III Flashcards
vsuccessive ionisaton enthalpy
2nd ionisation enthalpy
energy req to remove an e- from unipositive cation.
IE 1< IE2< Ie3«<
what is sublimation energy
Electron can not be removed from solid state of an atom, it has to be convert into gaseous form. Energy
required for conversion from solid state to gaseous state is called Sublimation energy.
units of ie
It is always an endothermic process (DH = +ve)
(d) It is measured in eV/atom (electron volt/atom) or Kcal/mole or KJ/mole
penetration effect
Order of attraction of subshells towards nucleus (Penetration power) is
in ground state from an
s > p > d > f
(b) ‘s’ subshell is more closer to nucleus, so more energy will be required to remove e– from s-subshell as
comparison to p,d & f-subshells.
excepton to ionisation energy
Ionisation Energy Ga > Al (due to Transition contraction)
l Ionisation Energy of 5d > 4d (due to lanthanide contraction)
how is ionisation energy related to stability of oxidation states
If the difference between two successive ionisation energies of an element > 16eV, then its lower oxidation
state is stable.
If the difference between two successive ionisation energies of an element < 11 eV, then its higher oxidation
state is stable.
how is ionisation energy used to determine valency
Number of valence electrons = number of lower values of IP before 1st highest jump.
successive electron gain enthalpies
2nd electron gain enthalpy is the energy charng occuring when an e- is added to a uningetaive anion
what egh of polyatomic ions
always +ve, endothermic
factors affecting electron gain enthaloy
atomic size is inversely prop to electrom gain enhaloy
nuclear charge is directly prop to electron gin enthalpy
Stability of completely filled or half filled orbitals : Electron affinity of elements having
full-filled or half filled configuration is very less or zero so for these elements electron gain enthalpy
(DH will be positive.
how are IE and delta eg H defined
Ionization energy and electron affinity are defined at absolute zero
(zero kelvin).
how does acidic strength and basic strength vary with electronegativity
acidic strength is directly proportional to electronegativity
basic strength is inversely proportional to electronegativity.
how does acidic strength and basic strength vary with period/grp
the acidic strength decreases down a grp while basic strength increases
the basic strength decreases across a period while acidic strength increases.
amphoteric oxides
ZnO
Al2O3
SnO
SnO2
BeO
PbO
Sb2O3
what is stability of hydrides
the stability of hydrides decreases with the decrease in electronegativity of the other atom. The tendency to hydrogen increases. Bond strength decreases.
