Colours

Question 1

Fe 2+ Aqua ion

Answer 1

[Fe(H2O)6]2+
Pale Green
Solution

Question 2

Co 2+ Aqua ion

Answer 2

[Co(H2O)6]2+
Pink
Solution

Question 3

Cu 2+ Aqua ion

Answer 3

[Cu(H2O)6]2+
Pale Blue
Solution

Question 4

Fe 3+ Aqua ion

Answer 4

[Fe(H2O)6]3+
Yellow
Solution

Question 5

Al 3+ Aqua ion

Answer 5

[Al(H2O)6]3+
Colourless
Solution

Question 6

Cr 3+ Aqua ion

Answer 6

[Fe(H2O)6]2+
Green
Solution

Question 7

Fe 2+ with dilute OH- or NH3

Answer 7

Fe(H2O)4(OH-)2
Green
Ppt

Question 8

Co 2+ with dilute OH- or NH3

Answer 8

Co(H2O)4(OH-)2
Blue
Ppt

Question 9

Cu 2+ with dilute OH- or NH3

Answer 9

Cu(H2O)4(OH-)2
Pale Blue
Ppt

Question 10

Fe 3+ with dilute OH- or NH3

Answer 10

Fe(H2O)3(OH-)3
Brown
Ppt

Question 11

Al 3+ with dilute OH- or NH3

Answer 11

Al(H2O)3(OH-)3
White
Ppt

Question 12

Cr 3+ with dilute OH- or NH3

Answer 12

Cr(H2O)3(OH-)3
Green
Ppt

Question 13

Fe 2+ with excess OH-

Answer 13

Fe(H2O)4(OH-)2
Green
Ppt

Question 14

Co 2+ with excess OH-

Answer 14

Co(H2O)4(OH-)2
Blue
Ppt

Question 15

Cu 2+ with excess OH-

Answer 15

Cu(H2O)4(OH-)2
Pale Blue
Ppt

Question 16

Fe 3+ with excess OH-

Answer 16

Fe(H2O)3(OH-)3
Brown
Ppt

Question 17

Al 3+ with excess OH-

Answer 17

[Al(OH-)4(H2O)2]3-
White
Ppt

Question 18

Cr 3+ with excess OH-

Answer 18

[Cr(OH-)6]3-
Green
Ppt

Question 19

What will be produced if Fe(H2O)4(OH-)2 is oxidised by air?

And what would be observed?

Answer 19

Fe(H20)3(OH-)3
Brown
Solution

Question 20

What will be produced if Co(H2O)4(OH-)2 or[Co(NH3)6]2+ is oxidised by air?
And what would be observed?

Answer 20

Co(III) Complex Ion
Brown
Solution

Question 21

Fe 2+ with excess NH3

Answer 21

Fe(H2O)4(OH-)2
Green
Ppt

Question 22

Co 2+ with excess NH3

Answer 22

[Co(NH3)6]2+
Pale Brown
Solution

Question 23

Cu 2+ with excess NH3

Answer 23

[Cu(H2O)2(NH3)4]2+
Deep Blue
Solution

Question 24

Fe 3+ with excess NH3

Answer 24

Fe(H2O)3(OH-)3
Brown
Ppt

Question 25

Al 3+ with excess NH3

Answer 25

Al(H2O)3(OH-)3 White Ppt

Question 26

Cr 3+ with excess NH3

Answer 26

[Cr(NH3)6]2+ Purple Solution

Question 27

Fe 3+ with CO3 2-

Answer 27

Fe(H2O)3(OH-)3 + CO2 Brown Ppt

Question 28

Al 3+ with CO3 2-

Answer 28

Al (H2O)3(OH-)3 + CO2 White Ppt

Question 29

Cr 3+ with CO3 2-

Answer 29

Cr(H2O)3(OH-)3 + CO2 Green Ppt

Question 30

Fe 2+ with CO3 2-

Answer 30

FeCO3 Green Ppt

Question 31

Co 2+ with CO3 2-

Answer 31

CoCO3 Pink Ppt

Question 32

Cu 2+ with CO3 2-

Answer 32

CuCO3 Green - Blue Ppt

Question 33

Co 2+ with conc HCL

Answer 33

[CoCl4]2- Blue Solution

Question 34

Cu 2+ with conc HCL

Answer 34

[CuCl4]2- Yellow Solution