Aqueous Ions

Question 1

What happenes if you put a transition metal into salt solution

Answer 1

It will dissolve and become its ions

the metal ion is then surrounded by 6 water ligands

Question 2

What colour is the complex [Fe(H2O)6]2+

Answer 2

Green

central metal charge: Fe2+

Question 3

What colour is the complex [Cu(H2O)6]2+

Answer 3

Blue

central metal charge: Cu2+

Question 4

What colour is the complex [Fe(H2O)6]3+

Answer 4

Purple
- often brown due to presence of small amounts of [Fe(H2O)5(OH)]2+

central metal charge: Fe3+

Question 5

What colour is the complex [Al(H2O)6]3+

Answer 5

Colourless

central metal charge: Al3+

Question 6

What does Amphoteric mean

Answer 6

can act as an acid AND a base

Question 7

what metal is an amphoteric

Answer 7

Aluminium

Question 8

What is the equation and observation for the addition of NaOH dropwise to [Cu(H2O)6]2+

Answer 8

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

blue solution forms a blue ppt

Question 9

What type of reaction is the addition of NaOH to a complex

Answer 9

acid base reaction

Question 10

What is the equation and observation for the addition of excess NaOH to [Cu(H2O)6]2+

Answer 10

Same equation as dropwise

No further change

Question 11

What is the equation and observation for the addition of NaOH dropwise to [Fe(H2O)6]2+

Answer 11

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

green solution forms green ppt

Question 12

What is the equation and observation for the addition of excess of NaOH to [Fe(H2O)6]2+

Answer 12

Same equation as drop wise

No further change

Question 13

What is the equation and observation for the addition of NaOH dropwise to [Fe(H2O)6]3+

Answer 13

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

brown solution forms a brown ppt

Question 14

What is the equation and observation for the addition of excess NaOH to [Fe(H2O)6]3+

Answer 14

Same equation as with dropwise

No further change

Question 15

What is the equation and observation for the addition of of NaOH dropwise to [Al(H2O)6]3+

Answer 15

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

colourless solution forms white ppt

Question 16

What is the equation for the addition of excess NaOH to [Al(H2O)6]3+

Answer 16

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

Question 17

What is the equation and observation for the addition of NH3 dropwise to [Cu(H2O)6]2+

Answer 17

[Cu(H2O)6]2+ + 2NH3- > Cu(H2O)4(OH)2 + 2N+H4

blue solution forms a blue ppt

Question 18

What is the equation and observation for the addition of conc NH3 to [Cu(H2O)6]2+

Answer 18

ligand substation reaction

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

Blue ppt forms dark blue solution

Question 19

What happens to Fe(H2O)4(OH)2 when left in standing air

Answer 19

it is oxidised to Fe(H2O)3(OH)3 and forms a brown ppt

Question 20

What is the equation and observation for the addition of NH3 dropwise to [Fe(H2O)6]2+

Answer 20

[Fe(H2O)6]2+ + 2NH3- > Fe(H2O)4(OH)2 + 2N+H4

Question 21

What is the equation and observation for the addition of conc NH3 to [Fe(H2O)6]2+

Answer 21

Same as equation with dropwise

No further change

Question 22

What is the equation and observation for the addition of NH3 dropwise to [Fe(H2O)6]3+

Answer 22

[Fe(H2O)6]3+ + 3NH3 > Fe(H2O)3(OH)3 + 3N+H4

Green solution forms green ppt

Question 23

What is the equation and observation for the addition of conc NH3 to [Fe(H2O)6]3+

Answer 23

Same as the equation with dropwise

No further change

Question 24

What is the equation and observation for the addition of dilute NH3 dropwise to [Al(H2O)6]3+

Answer 24

[Al(H2O)6]3+ + 3NH3 > Al(H2O)3(OH)3 + 3N+H4

Colourless solution forms white ppt

Question 25

What is the equation and observation for the addition of **conc NH3** to [Al(H2O)6]3+

Answer 25

Same as the equation with dropwise No further change

Question 26

What is the equation and observation for the addition of **CO3 dropwise** to [Cu(H2O)6]2+

Answer 26

[Cu(H2O)6]2+ + CO3^2- > CuCO3 + 6H2O Blue solution forms blue/green ppt

Question 27

What is the equation and observation for the addition of **CO3 dropwise** to [Fe(H2O)6]2+

Answer 27

[Fe(H2O)6]2+ + CO3^2- > FeCO3 + 6H2O Green solution forms green ppt

Question 28

What is the equation and observation for the addition of **CO3 dropwise** to [Fe(H2O)6]3+

Answer 28

Acid base reaction 2[Fe(H2O)6]3+ + 3CO3^2- > 2Fe(H2O)3(OH)3 + 3H2O + 3CO2 Brown solution forms brown ppt Effervescence due to CO2

Question 29

What is the equation and observation for the addition of **CO3 dropwise** to [Al(H2O)6]3+

Answer 29

Acid base reaction 2[Al(H2O)6]3+ + 3CO3^2- > 2Al(H2O)3(OH)3 + 3H2O + 3CO2 Colourless solution forms white ppt Effervescence due to CO2

Question 30

Why do Fe3+ and Al3+ complexes have different reaction with CO3

Answer 30

3+ ions are more acidic - Fe3+ & Al3+ are smaller ions w/ a greater charge - O-H bond in water are more polarised - More h+ are released

Question 31

What is the equation and observation for the addition of **conc HCl dropwise** to [Cu(H2O)6]2+

Answer 31

Ligand substitution reaction [Cu(H2O)6]2+ + 4Cl- > [CuCl4]^2- + 6H2O Blue solution forms yellow/green ppt

Question 32

What is the equation and observation for the addition of **conc HCl dropwise** to [Fe(H2O)6]2+

Answer 32

Ligand substitution reaction [Fe(H2O)6]2+ + 4Cl- > [FeCl4]^2- + 6H2O Green solution forms green ppt

Question 33

What is the equation and observation for the addition of **conc HCl dropwise** to [Fe(H2O)6]3+

Answer 33

Ligand substitution reaction [Fe(H2O)6]3+ + 4Cl- > [FeCl4]- + 6H2O Brown solution forms brown ppt

Question 34

What is the equation and observation for the addition of **conc HCl dropwise** to [Al(H2O)6]3+

Answer 34

Ligand substitution reaction [Fe(H2O)6]2+ + 4Cl- > [FeCl4]- + 6H2O Colourless solution forms white ppt

Question 35

What is NaCO3

Answer 35

a weak base