Transition Metals Allery

Question 1

Cu2+ in aqueous solutions

Answer 1

[Cu(H2O)6] 2+
Blue

Question 2

Fe2+ in aqueous solutions

Answer 2

[Fe(H20)6]2+
Pale green

Question 3

Fe3+ in aqueous solutions

Answer 3

[Fe(H2O)6]3+
Yellow

Question 4

Mn2+ in aqueous solutions

Answer 4

[Mn(H2O)6]2+
Pale pink

Question 5

Cr3+ in aqueous solutions

Answer 5

[Cr(H2O)6]3+ -> violet
Green

Question 6

Adding OH- or NH3 to aqueous Cu2+

Answer 6

Product: Cu(OH)2(H2O)4 Blue ppt

Equations:
1. [Cu(H2O)6]2+ + 2OH- -> Cu(OH)2(H2O)4 + 2H2O
2. [Cu(H2O)6]2+ + 2NH3 -> Cu(OH)2(H2O)4 + 2NH4+

Question 7

Adding OH- or NH3 to aqueous Fe2+

Answer 7

Product: Fe(OH)2(H2O)4 Dirty Green ppt

Equations:
1. [Fe(H2O)6]2+ + 2OH- -> Fe(OH)2(H2O)4 + 2H2O
2. [Fe(H2O)6]2+ + 2NH3 -> Fe(OH)2(H2O)4 + 2NH4+

Question 8

Adding OH- or NH3 to aqueous Fe3+

Answer 8

Product: Fe(OH)3(H2O)3 Orange ppt

Equations:
1. [Fe(H2O)6]3+ + 3OH- -> Fe(OH)3(H2O)3 + 3H2O
2. [Fe(H2O)6]3+ + 3NH3 -> Fe(OH)3(H2O)4 + 3NH4+

Question 9

Adding OH- or NH3 to aqueous Mn2+

Answer 9

Product: Mn(OH)2(H2O)4 Pink ppt

Equations:
1. [Mn(H2O)6]2+ + 2OH- -> Mn(OH)2(H2O)4 + 2H2O
2. [Mn(H2O)6]2+ + 2NH3 -> Mn(OH)2(H2O)4 + 2NH4+

Question 10

Adding OH- or NH3 to aqueous Cr3+

Answer 10

Product: Cr(OH)3(H2O)3 Green-grey ppt

Equations:
1. [Cr(H2O)6]3+ + 3OH- -> Cr(OH)3(H2O)3 + 3H2O
2. [Cr(H2O)6]3+ + 3NH3 -> Cr(OH)3(H2O)4 + 3NH4+

Question 11

Adding excess OH- to Cu(OH)2(H2O)4 ppt

Answer 11

insoluble so no change

Question 12

Adding excess OH- to Fe(OH)2(H2O)4 ppt

Answer 12

insoluble so no change

Question 13

Adding excess OH- to Fe(OH)3(H20)3 ppt

Answer 13

insoluble so no change

Question 14

Adding excess OH- to Mn(OH)2(H2O)4 ppt

Answer 14

insoluble so no change

Question 15

Adding excess OH- to Cr(OH)3(H2O)3 ppt

Answer 15

Cr(OH)6 3- (aq)
Dark green solution

Question 16

Adding excess NH3 to Cu(OH)2(H2O)4 ppt

Answer 16

[Cu(NH3)(H20)2] 2+
dark blue solution

Question 17

Adding excess NH3 to Fe(OH)2(H2O)4 ppt

Answer 17

Insoluble so no change

Question 18

Adding excess NH3 to Fe(OH)3(H2O)3 ppt

Answer 18

Insoluble so no change

Question 19

Adding excess NH3 to Mn(OH)2(H2O)4 ppt

Answer 19

insoluble so no change

Question 20

Adding excess NH3 to Cr(OH)3(H2O)3 ppt

Answer 20

Cr(NH3)6 3+ (aq)
Purple solution

Question 21

CuCl4 2- (aq)

Answer 21

yellow
Add excess HCL to Cu2+

Question 22

CoCl4 2- (aq)

Answer 22

blue solution
formed from CoCl2. 6H2O and excess HCl or H2O

Question 23

MnO4- (aq)

Answer 23

purple

Question 24

Mn2+ (aq)

Answer 24

pale pink

Question 25

Cr2O7 2- (aq)

Answer 25

orange

Question 26

CrO4 2- (aq)

Answer 26

yellow

Question 27

Cr2+ (aq)

Answer 27

pale blue

Question 28

Cl2 (aq) and hexane

Answer 28

pale green

Question 29

Br2 (aq) and hexane

Answer 29

orange

Question 30

I2 (aq)

Answer 30

brown

Question 31

I2 in hexane

Answer 31

violet

Question 32

What happens when you add I- to [Cu(H2O)6]2+?

Answer 32

CI(s) White ppt I2(l) Brown solution

Question 33

What happens when you add hot dilute H2SO4 to Cu2O(s)?

Answer 33

CuSO4 (an) blue solution Cu(s) brown ppt

Question 34

What happens when Fe3+ reacts with KI?

Answer 34

2Fe2+ -> pale green solution I2 -> brown solution

Question 35

What happens when Copper (ll) sulfate reacts with potassium iodide?

Answer 35

CuI -> white solid I2 -> brown solution