D block elements

Question 1

Sc3+

Answer 1

Colourless

Question 2

Ti4+

Answer 2

Colourless

Question 3

Cr3+

Answer 3

Violet

Question 4

Mn2+

Answer 4

Pale pink

Question 5

Fe3+

Answer 5

Brown yellow

Question 6

Fe2+

Answer 6

Pale green

Question 7

Co2+

Answer 7

Pink

Question 8

Ni2+

Answer 8

Green

Question 9

Cu2+

Answer 9

Blue

Question 10

Cu+

Answer 10

Colourless

Question 11

Zn2+

Answer 11

Colourless

Question 12

MnO4-

-

Answer 12

Purple

Question 13

MnO42-

Answer 13

Green

Question 14

CrO42-

Answer 14

Yellow

Question 15

Cr2O72-

Answer 15

Orange

Question 16

Transition and non-transition d block elements

Answer 16

d block elements contain incompletely filed d subshell at elemental state or with the ability to form at least one stable ion with incompletely filled d subshell are called transition elements. Therefore, d block elements producing ions only with d10 configurations are considered as non-transition elements.(Zn,Cd,Hg)

Question 17

Properties of transition elements

Answer 17

Has less variations in atomic radii than main group elements. The atomic radii decreases slightly and then increase.
Nuclear charge increases across a group.
But at the end elements like Zn, Cu atomic radii increases as repulsion between electrons are high due to the pairing of electrones.

Question 18

Which d block element has the highest melting point

Answer 18

Cr- theoretical value
V- practically
Higher the number of unpaired electrons higher the melting point (refer)

Question 19

Mn3+

Answer 19

Violet

Question 20

V2+

Answer 20

violet

Question 21

V3+

Answer 21

green

Question 22

Ti3+

Answer 22

purple

Question 23

NO

Answer 23

nitrosyl- neutral

Question 24

CO

Answer 24

carbonyl- neutral

Question 25

C2H5N

Answer 25

pyridine-neutral

Question 26

MnO2

Answer 26

Dark brown/black

Question 27

under acidic conditions, MnO4- reduces to

Answer 27

Mn2+.

Question 28

H3O+

Answer 28

Hydronium

Question 29

What is coordination number

Answer 29

The no. of coordination bonds formed between the central metal ion and ligands. Depends on size, charge, nature of the ligand and the electronic configuration of the central metal ion.

Question 30

Factors affecting the color of complexes

Answer 30

Central metal ion, oxidation state of the central metal ion and the nature of the ligand

Question 31

Colors of complexes | Aqueous

Answer 31

Same color as the metal ion

Question 32

Cr(OH)3

Answer 32

Blue-green

Question 33

Mn(OH)2

Answer 33

white/ cream

Question 34

Fe(OH)2

Answer 34

Dirty green

Question 35

Fe(OH)3

Answer 35

Reddish-brown

Question 36

Co(OH)2

Answer 36

Pink

Question 37

[Co(OH)4]2-

Answer 37

Deep-blue

Question 38

Ni(OH)2

Answer 38

green

Question 39

Cu(OH)2

Answer 39

Blue

Question 40

Zn(OH)2

Answer 40

white

Question 41

[Zn(OH)4]2-

Answer 41

Colorless

Question 42

Cr(OH)3 -NH3

Answer 42

Blue-green

Question 43

Mn(OH)2 -NH3

Answer 43

White/ cream

Question 44

Fe(OH)2 -NH3

Answer 44

Dirty green ppt

Question 45

Fe(OH)3 -NH3

Answer 45

Reddish-brown ppt

Question 46

[Co(NH3)6]2+

Answer 46

yellowish-brown

Question 47

[Co(NH3)6]3+

Answer 47

Brownish-red

Question 48

[Ni(NH3)6]2+

Answer 48

Blue

Question 49

[Cu(NH3)4]2+

Answer 49

Deep blue

Question 50

[Zn(NH3)4]2+

Answer 50

Colourless

Question 51

[CrCl6]3-

Answer 51

Blue-violet

Question 52

[MnCl4]2-

Answer 52

Greenish yellow

Question 53

[FeCl4]-

Answer 53

Yellow

Question 54

[Co(Cl)4]2-

Answer 54

Blue

Question 55

[NiCl4]2-

Answer 55

Yellow

Question 56

[CuCl4]2-

Answer 56

Yellow

Question 57

[ZnCl4]2-

Answer 57

Colourless

Question 58

[Cr(H2O)6]3+ + 3NH3 (aq)

Answer 58

Cr(OH)3(s) + 3NH4+(aq) + 3H2O(l) | Blue-green gelatinous ppt

Question 59

[Co(H2O)6]2+(aq) + 2OH-(aq)

Answer 59

Co(OH)2(s) + 6H2O(l) | Pink ppt

Question 60

Co(OH)2(s) + 2OH-(aq)

Answer 60

[Co(OH)4]2-(aq) | Deep blue solution

Question 61

[Co(H2O)6]2+(aq) + 6NH3 (aq)

Answer 61

[Co(NH3)6]2+(aq) + 6H2O(l) Forms a yellowish-brown solution however due to the auto oxidation it forms[Co(NH3)6]3+(aq) which is brownish-red in colour.

Question 62

Co(H2O)6]2+(aq) + 4Cl-(aq)

Answer 62

[CoCl4]2-(aq) + 6H2O(l) | Forms a blue solution

Question 63

[Ni(H2O)6]2+(aq) + 2OH-(aq)

Answer 63

Ni(OH)2(s) + 6H2O(l) | Forms a green precipitate

Question 64

[Ni(H2O)6]2+(aq) + 6NH3 (aq)

Answer 64

[Ni(NH3)6]2+(aq) + 6H2O(l) | Forms a deep-blue solution

Question 65

[Ni(H2O)6]2+(aq) + 4Cl-(aq)

Answer 65

[NiCl4]2-(aq) + 6H2O(l) | Forms a yellow solution

Question 66

[Mn(H2O)6]2+(aq) + 2OH-(aq)

Answer 66

Mn(OH)2(s) + 6H2O(l) | Forms white/cream ppt

Question 67

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

Answer 67

Fe(OH)3(s) + 6H2O(l) | Forms reddish-brown ppt

Question 68

[Cu(H2O)6]2+(aq) + 2OH-(aq)

Answer 68

Cu(OH)2(s) + 6H2O(l) | Pale blue solution turns into blue solution

Question 69

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

Answer 69

[Cu(NH3)4]2+(aq) + 6H2O(l) | Forms a deep-blue complex

Question 70

[Cu(H2O)6]2+(aq) + 4Cl-(aq)

Answer 70

[CuCl4]2-(aq) + 6H2O(l) | Solution turns yellow

Question 71

[Zn(H2O)6]2+(aq) +2OH-(aq)

Answer 71

Zn(OH)2(s) + 6H2O(l) | Colorless solution turns in to a white precipitate.

Question 72

Metal cations which forms precipitates with Cl

Answer 72

Pb Ag Hg

Question 73

Colors of carbonates formed by group 2 metals

Answer 73

All carbonates formed by group 2 metals are white.