Reactions Of Ipns In Solutipn Flashcards
What do most metal actions exist as in aqueous solution
The hexaaqua complex ion
What kind of ions do main group metals form
Colourless
What are most transition metal ions
Coloured
Why are lost transition metal ions coloured
-incomplete d sub shell
-some wavelengths of vidible light absorbed
-d electrons ground state to excited state -
Remaining colours of visible light transmitted
Copper 2 hexaaqua ion colour
Blue
Iron 3 hexaaqua ion colour
Purple
Aluminium 3 hexaaqua ion colour
Colourless
What is there a hydrolysis reaction beteeen in solution
Metal aqua ion and water
What does the charge on the metal job cause the electron density in the water ligand to do
Move closer to metal ion- water ligand polarised
What happens if the metal ion had enough polarising power
Bonds in water weakened
One of bonds breaks and proton donated to water molecule
What is relationship between pKa and strength of acidity of hexaaqua ion
Lower pka- stronger acid- equilibrium lies further to right
What is the difference in acidity due to in iron 2 and iron 3
Charge/size ratios
Why is iron 3 more acidic than iron 2
Smaller and more highly charged and therefore able to polarise water ligands more
OH bonds in water weakened more readily and protons more easily donated
Equations for al3+ hexaaqua with water
[Al(H2O)6]3+ + H2O > [Al(H2O)5(OH)]2+ + H3O+
Why will al3 hexaaqua be more acidic than copper 2 hexaaqua
Al3 ions smaller and more highly charged therefore able to polarise water ligands more, weaken OH bonds therefore donate H+ ions more readily
What does adding a base to an aqueous solution of the metal aqua ion produce
Insoluble precipitates of the metal hydroxide
Equation for adding hydroxide to metal aqua ion
[M(H2O)6]3+ + OH- > [M(H2O)5(OH)]2+ + H2O
What happens to the equilibrium if you add more OH- ions to metal aqua ion
Equilibrium shifts to the right to oppose the increase in [OH-] and a new equilibrium set up
Equation for new equilibrium set up after adding more OH- ions to metal aqua ion
[M(H2O)5(OH)]2+ + OH- > [M(H2O)4(OH)2]+ + H2O
What happens to the equivlirum if you add FURTHER OH- ions to the metal aqua ion
Equilibrium shift to the right to oppose increase in [OH-] and final equilibrium set up