24 reaction of aqueous ions Flashcards
define hydration enthalpy
the standard enthalpy change when one mole of gaseous ions is converted to one mole of aqueous ions
when ions are hydrated what are positive ions attracted to?
slightly negative oxygen in water molecules
when ions are hydrated what are negative ions attracted to?
slightly positive hydrogens in water molecules
what is a complex ion?
central atom or ion surrounded by ligands
what is a coordinate bond?
shared pair of electrons that have both come from the same atom
define ligand
ion or molecule with a lone pair of electrons which can form a coordinate bond with a transition metal ion
define coordination number
number of coordinate bonds a transition metal ion forms
what are 4 hexa aqua complex ions?
[Cu(H2O)6]2+
[Fe(H2O)6]2+
[Fe(H2O)6]3+
[Al(H2O)6]3+
what is each hexa aqua complex ion’s colour?
[Cu(H2O)6]2+ = blue solution
[Fe(H2O)6]2+ = pale green solution
[Fe(H2O)6]3+ = yellow brown solution
[Al(H2O)6]3+ = colourless solution
what colour is [Cu(H2O)6]2+?
blue solution
what colour is [Fe(H2O)6]2+?
pale green solution
what colour is [Fe(H2O)6]3+?
yellow brown solution
what colour is [Al(H2O)6]3+
colourless solution
which hexa aqua complex ions are more acidic?
3+ ions
why are the 3+ ions more acidic?
smaller with higher charge
more polarising
attracts lone pair in O
weakens O-H
can release H+ more easily