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
write an equation to show [Fe(H2O)6]3+ acting as an acid
[Fe(H2O)6]3+ -> [Fe(H2O)5(OH)]2+ + H+
what 3 things do all the hexa aqua complex ions react with?
Na2CO3
NaOH
NH3
how does [Fe(H2O6)]2+ react with Na2CO3?
state the observation
[Fe(H2O)6]2+ + CO3 2- -> FeCO3 (s) + 6H2O
green solution -> green precipitate
how does [Fe(H2O6)]2+ react with NaOH?
state the observation
[Fe(H2O6)]2+ + 2OH- -> [Fe(H2O)4(OH)2] (s)+ 2H2O
green solution -> green precipitate
how does [Fe(H2O6)]2+ react with NH3?
state the observation
[Fe(H2O6)]2+ + 2NH3 -> [Fe(H2O)4(OH)2] (s) + 2NH4+
green solution -> green precipitate
how does [Cu(H2O)6]2+ react with Na2CO3?
state the observation
[Cu(H2O)]2+ + CO3 2- -> CuCO3 (s) + 6H2O
blue solution -> blue green precipitate
how does [Cu(H2O)6]2+ react with NaOH?
state the observation
[Cu(H2O)6]2+ + 2OH- -> [Cu(H2O)4(OH)2] (s) + 2H2O
blue solution -> blue precipitate
how does [Cu(H2O)6]2+ react with NH3?
state the observation
[Cu(H2O)6]2+ + 2NH3 -> [Cu(H2O)4(OH)2] (s) + 2NH4+
blue solution -> blue precipitate
what other equation can also happen after [Cu(H2O)6] has reacted with 2NH3?
can react with an excess of ammonia
how does [Cu(H2O)4(OH)2] react with an excess of ammonia?
state the observation
[Cu(H2O)4(OH)2] + 2NH3 -> [Cu(H2O)2(NH3)4]2+ + 2H2O + 2OH-
blue precipitate -> deep blue solution
how does [Fe(H2O)6]3+ react with Na2CO3?
state the observation
[Fe(H2O)6]3+ + 3CO3 2- -> 2[Fe(H2O)3(OH)3] + 3CO2 + 3H2O
yellow brown solution -> brown precipitate with effervescence
how does [Fe(H2O)6]3+ react with NaOH?
state the observation
[Fe(H2O)6]3+ + 3OH- -> [Fe(H2O)3(OH)3] + 3H2O
yellow brown solution -> brown precipitate
how does [Fe(H2O)6]3+ react with NH3?
state the observation
[Fe(H2O)6]3+ + 3NH3 -> [Fe(H2O)3(OH)3] + 3NH4+
yellow brown solution -> brown precipitate
how does [Al(H2O)6]3+ react with Na2CO3?
state the observation
[Al(H2O)6]3+ + 3CO3 2- -> [Al(H2O)3(OH)3] + 3CO2 +3H2O
colourless solution -> white precipitate with effervescence
how does [Al(H2O)6]3+ react with NaOH?
state the observation
[Al(H2O)6]3+ + 3OH- -> [Al(H2O)3(OH)3] + 3H2O
colourless solution -> white precipitate
how does [Al(H2O)6]3+ react with NH3?
state the observation
[Al(H2O)6]3+ + 3NH3 -> [Al(H2O)3(OH)3] + 3NH4+
colourless solution -> white precipitate
what other equation can happen after [Al(H2O)6]3+ reacts with NaOH?
can react with another NaOH
how does [Al(H2O)3(OH)3] react with an another OH?
state the observation
[Al(H2O)3(OH)3] + OH- -> [Al(H2O)2(OH)4]- + H2O
white precipitate -> colourless solution
what does amphoteric mean?
can act as an acid or a base
show [Al(H2O)3(OH)3] acting as a base
[Al(H2O)3(OH)3] + 3H+ -> [Al(H2O)6]3+
show [Al(H2O)3(OH)3] acting as an acid
[Al(H2O)3(OH)3] + OH- -> [Al(H2O)2(OH)4]- + H2O
how does [Cu(H2O)6]2+ react with HCl?
state the observation
[Cu(H2O)6]2+ + 4Cl- -> [CuCl4]2- + 6H2O
blue solution -> yellow solution