Reactions Of Ipns In Solutipn

Question 1

What do most metal actions exist as in aqueous solution

Answer 1

The hexaaqua complex ion

Question 2

What kind of ions do main group metals form

Answer 2

Colourless

Question 3

What are most transition metal ions

Answer 3

Coloured

Question 4

Why are lost transition metal ions coloured

Answer 4

-incomplete d sub shell
-some wavelengths of vidible light absorbed
-d electrons ground state to excited state -
Remaining colours of visible light transmitted

Question 5

Copper 2 hexaaqua ion colour

Answer 5

Blue

Question 6

Iron 3 hexaaqua ion colour

Answer 6

Purple

Question 7

Aluminium 3 hexaaqua ion colour

Answer 7

Colourless

Question 8

What is there a hydrolysis reaction beteeen in solution

Answer 8

Metal aqua ion and water

Question 9

What does the charge on the metal job cause the electron density in the water ligand to do

Answer 9

Move closer to metal ion- water ligand polarised

Question 10

What happens if the metal ion had enough polarising power

Answer 10

Bonds in water weakened

One of bonds breaks and proton donated to water molecule

Question 11

What is relationship between pKa and strength of acidity of hexaaqua ion

Answer 11

Lower pka- stronger acid- equilibrium lies further to right

Question 12

What is the difference in acidity due to in iron 2 and iron 3

Answer 12

Charge/size ratios

Question 13

Why is iron 3 more acidic than iron 2

Answer 13

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

Question 14

Equations for al3+ hexaaqua with water

Answer 14

[Al(H2O)6]3+ + H2O > [Al(H2O)5(OH)]2+ + H3O+

Question 15

Why will al3 hexaaqua be more acidic than copper 2 hexaaqua

Answer 15

Al3 ions smaller and more highly charged therefore able to polarise water ligands more, weaken OH bonds therefore donate H+ ions more readily

Question 16

What does adding a base to an aqueous solution of the metal aqua ion produce

Answer 16

Insoluble precipitates of the metal hydroxide

Question 17

Equation for adding hydroxide to metal aqua ion

Answer 17

[M(H2O)6]3+ + OH- > [M(H2O)5(OH)]2+ + H2O

Question 18

What happens to the equilibrium if you add more OH- ions to metal aqua ion

Answer 18

Equilibrium shifts to the right to oppose the increase in [OH-] and a new equilibrium set up

Question 19

Equation for new equilibrium set up after adding more OH- ions to metal aqua ion

Answer 19

[M(H2O)5(OH)]2+ + OH- > [M(H2O)4(OH)2]+ + H2O

Question 20

What happens to the equivlirum if you add FURTHER OH- ions to the metal aqua ion

Answer 20

Equilibrium shift to the right to oppose increase in [OH-] and final equilibrium set up

Question 21

Equation for final equilibrium set up after adding further OH- ions to metal aqua ions

Answer 21

[M(H2O)4(OH)2] + OH- > [M(H2O)3(OH)3] + H2O

Question 22

Why does [M(H2O)3(OH)3] precipitate out

Answer 22

It’s neutral and insoluble

Question 23

Overall equation metal aqua ion and hydroxide

Answer 23

[M(H2O)6]3+ + 3OH- > [M(H2O)3(OH)3] + 3H2O

Question 24

Iron 2 hexaaqua ion colour

Answer 24

Green

Question 25

Colour of PPT iron 2 and NAOH

Answer 25

Brown

Question 26

How can reaction between iron 2 hexaaqua and sodium hydroxide be reversed

Answer 26

Adding acid

Question 27

What colour ppt does Al3+ hexaaqua form with hydroxide

Answer 27

White

Question 28

Equation for aluminium hydroxide acting as a base

Answer 28

[Al(H2O)3(OH)3] + 3H+ > [Al(H2O)6]3+

Question 29

Equation for aluminium hydroxide acting as an acid

Answer 29

[Al(H2O)3(OH)3] + OH- > [Al(H2O)2(OH)4]- + H2O

Question 30

What does the white ppt of aluminium hydroxide dissolve to form

Answer 30

A colourless solution

Question 31

Overall equation for metal hexaaqua ion with NAOH

Answer 31

[M(H2O)6]2+ + 2OH- > [M(H2O)4(OH)2] + 2H2O

Question 32

What colour ppt is formed from reaction of iron 2 hexaaqua and NAOH

Answer 32

Green/grey

Question 33

Why does green/green iron 2 PPT turn green when left to stand in air

Answer 33

Oxidation to iron 3 hydroxide

Question 34

Equation for reaction of iron 2 oxide to iron 3 oxide

Answer 34

[Fe(H2O)4(OH)2] > [Fe(H2O)3(OH)3] + H+ + e-

Question 35

What colour ppt does copper 2 hexaaqua form with sodium hydroxide

Answer 35

Blue

Question 36

Why is ammonia able to react with metal aqua ions to produce metal hydroxides

Answer 36

It’s a weak base

Question 37

Reaction of iron 3 hexaaqua with aqueousammonia

Answer 37

[Fe(H2O)6]3+ + 3NH3 > [Fe(H2O)3(OH)3] + 3NH4+ Brown ppt

Question 38

Reaction of aluminium 3 hexaaqua with aqueous ammonia

Answer 38

[Al(H2O)6]3+ + 3NH3 > [Al(H2O)3(OH)3] + 3NH4+ White ppt

Question 39

Why can’t ammonia hydrolyse aluminium hydroxide further

Answer 39

It’s a weak base

Question 40

Reaction of iron 2 hexaaqua with aqueous ammonia

Answer 40

[Fe(H2O)6]2+ + 2NH3 > [Fe(H2O)4(OH)2] + 2NH4+ Green grey ppt

Question 41

Reaction of copper 2 aqueous ammonia

Answer 41

[Cu(H2O)6]2+ + 2NH3 > [Cu(H2O)4(OH)2] + 2NH4+ Blue ppt

Question 42

What can be formed by a ligand substitution reaction when an excess of ammonia is added to the copper 2 hydroxide precipitate

Answer 42

A new complex

Question 43

Equation for copper 2 hydroxide and excess ammonia

Answer 43

[Cu(H2O)4(OH)2] + 4NH3 > [Cu(H2O)2(NH3)4 2+ + 2H2O + 2OH- Deep blue soln

Question 44

Overall reaction between hexaaqua copper II ion and excess ammonia

Answer 44

[Cu(H2O)6]2+ + 4NH3 > [Cu(NH3)4(H2O)2]2+ + 2H2O

Question 45

What do 2+ metal ions react with sodium carbonate to form

Answer 45

Insoluble metal carbonates

Question 46

Reaction of copper 2 hexaaqua with sodium carbonate

Answer 46

[Cu(H2O)6]2+ + CO32- > CuCO3 + 6H2O Blue soln to blue green ppt

Question 47

Reaction iron 2 hexaaqua and aqueous sodium carbonate

Answer 47

[Fe(H2O)6]2+ + CO32- > FeCO3 + 6H2O Green soln to green grey ppt

Question 48

Why do 3+ metal ions form the hydroxide and release carbon dioxide gas when reacting with sodium carbonate

Answer 48

They’re stronger acids

Question 49

Reaction iron 3 with sodium carbonate

Answer 49

2[Fe(H2O)6]3+ + 3CO32- > 2Fe(H2O)3(OH)3] + 3CO2 + 3H2O Orange soln to brown ppt

Question 50

Equation aluminium 3 with sodium carbonate

Answer 50

2[Al(H2O)6]3+ + 3CO32- > 2[Al(H2O)3(OH)3] + 3CO2 + 3H2O Colourless soln Fizz