Transition Metals Colours

Question 1

Colour of [Cu(H20)6]2+

Answer 1

Light Blue solution

Question 2

Colour of [Cu(H20)4(OH)2]

Answer 2

Light blue ppt

Question 3

Colour of [Cu(NH3)4(H2O)2]2+

Answer 3

Dark blue solution

Question 4

Colour of [CuCl4]2-

Answer 4

Yellow solution

Question 5

Colour produced in redox reaction with Cu2+ and I-

Answer 5

white ppt - CuI
Brown solution I2

Question 6

Colours produced in a disproportionation reaction with Cu+ and H2SO4

Answer 6

CuSo4 = blue solution
Cu = brown solid

Question 7

colour of [Cr(H20)6]3+

Answer 7

pale purple solution

Question 8

Colour of [Cr(OH)3(H20)3]

Answer 8

dark green ppt

Question 9

colour of [Cr(NH3)6]3+

Answer 9

dark purple solution

Question 10

colour of [Cr(OH)6]3-

Answer 10

dark green solution

Question 11

colour of (Cr2O7)2-

Answer 11

orange solution

Question 12

colour of (CrO4)2-

Answer 12

yellow solution

Question 13

colour of [Mn(H2O)6]2+

Answer 13

Pale pink solution

Question 14

Colour of [Mn(OH)2(H20)4]

Answer 14

pale brown ppt

Question 15

colour of [Fe(H20)6]2+

Answer 15

pale green solution

Question 16

colour of [Fe(OH)2(H20)4]

Answer 16

dark green ppt

Question 17

colour of [Fe(H20)6]3+

Answer 17

yellow solution

Question 18

Colour of [Fe(OH)3(H2O)3]

Answer 18

Orange brown ppt

Question 19

what is produced when [Cu(H2O)6]2+ reacts with dropwise base NH3/OH-

Answer 19

[CU(OH)2(H20)4] - pale blue ppt

Question 20

What happens when [Cu(H2O)6]2+ reacts with excess base NH3

Answer 20

[Cu(NH3)4(H2O)2]2+ is produced - dark blue solution

Question 21

What happens when [Cr(H20)6]3+ reacts with dropwise base (NH3/OH)

Answer 21

[Cr(OH)3(H20)3] forms - dark green ppt

Question 22

what happens when [Cr(H2O)6]3+ reacts with excess NH3

Answer 22

[Cr(NH3)6]3+ forms - purple solution

Question 23

what happens when [Cr(H2O)6]3+ reacts with excess OH-

Answer 23

[Cr(OH)6]3- forms - dark green solution

Question 24

what happens when [Mn(H2O)6]2+ reacts with dropwise base ( NH3/OH)

Answer 24

[Mn(OH)2(H20)4] forms - pale brown ppt

Question 25

what happens when [Fe(H20)6]2+ reacts dropwise with a base (NH3/OH)

Answer 25

[Fe(OH)2(H20)4] forms - dark green ppt

Question 26

what happens when [Fe(H20)6]3+ reacts with dropwise base (NH3/OH)

Answer 26

[Fe(OH)3(H2O)3] forms - orange brown ppt

Question 27

what is the colour change and compound formed when Cu2+ + Cl-

Answer 27

CuCl4 - yellow solution

Question 28

what is the colour change and compound formed when Cu2+ + I-

Answer 28

CuI - white ppt I2 - brown solution

Question 29

what is the colour change and compounds formed when Cu+ + H2SO4

Answer 29

CuS04 - blue solution Cu - brown solid

Question 30

what is the colour change and compound formed when [CoCl2.6H2O] + HCl

Answer 30

[CoCl4]2- dark blue solution

Question 31

what is the colour change and compound when Cr3+ is oxidised using H2O2

Answer 31

[CrO4]2- - yellow solution

Question 32

what is the colour change and compound formed in the reduction of CrO72-

Answer 32

Cr3+ formed - orange to green

Question 33

describe the colour change of the oxidation of Fe2+ to Fe3+ and the oxidising agent used

Answer 33

MnO42- is used as an oxidising agent colour change from purple to colourless

Question 34

describe the colour change and reducing agent used in the reduction of Fe3+ and Fe2+

Answer 34

reducing agent is KI orange brown to pale green

Question 35

what is the colour change and compounds formed in the reduction of Cu2+ to Cu+

Answer 35

uses KI as reducing agent colour change from pale blue solution to white solid - CuI brown solution - I2

Question 36

describe the disproportionation reaction of Cu+ with H2SO4

Answer 36

Cu+ is oxidised oxidation state changes from +1 to +2 in CuSO4 compound - blue solution Cu+ is reduced oxidation state changes from +1 to 0 in Cu compound - brown ppt

Question 37

describe the chemical test for Fe2+

Answer 37

add OH- dropwise dark green ppt will form add excess OH no further change

Question 38

describe the chemical test for Fe3+

Answer 38

add OH- dropwise yellow sol to brown ppt

Question 39

describe the chemical test of Cr3+

Answer 39

add OH- dropwise colour change from purple sol to green ppt

Question 40

describe the chemical test of Mn2+

Answer 40

add dropwise OH- colour change from pale pink sol to pale brown ppt

Question 41

Describe the chemical test of Cu2+

Answer 41

Add OH- dropwise observe pale blue solution to pale blue ppt

Question 42

describe the chemical test of NH4

Answer 42

heat with NaOH to produce NH3 gas hold red litmus paper near test tube opening should turn red litmus blue