Transition Elements

Question 1

True transition metal definition

Answer 1

D-block elements forming at least one stable ion with partially filled d-subshells (not Sc or Zn)

Question 2

Ligand definition

Answer 2

A molecule or ion that donates a pair of electrons to a central metal ion to form a coordinate bond

Question 3

Coordination number

Answer 3

The total number of coordinate bonds formed between the central metal ion and any ligands

Question 4

EDTA 4- use

Answer 4

Forms 6 coordinate bonds

Uses: detergents & foods as a stabiliser & prevents blood clotting

Question 5

Use of cis-platin

Answer 5

Important anti-cancer drug- prevents cell division

Question 6

Cu 2+ solution colour

Answer 6

Pale blue

Question 7

Fe 2+ solution colour

Answer 7

pale green

Question 8

Fe 3+ solution colour

Answer 8

pale yellow

Question 9

Mn 2+ solution colour

Answer 9

pale pink

Question 10

Cr 3+ solution colour

Answer 10

pale purple

in presence of H2SO4 = green solution

Question 11

Cu 2+ with NaOH

Answer 11

pale blue ppt
CU2+(aq) + 2OH-(aq) -> Cu(OH)2(s)
OR
[Cu(H2O)6]2+ + 2OH- -> Cu(OH)2(H2O)4 + 2H2O
note if w/NH3 then + 2NH4+

Question 12

Fe 2+ with NaOH

Answer 12

green ppt Fe(OH)2

oxidises to brown in air Fe(OH)3

Question 13

Fe 3+ with NaOH

Answer 13

rusty brown ppt Fe(OH)3
Fe3+(aq) + 3OH-(aq) -> Fe(OH)3(s)
OR
[Fe(H2O)6]3+ + 3OH- -> [Fe(OH)3(H2O)3] (s) + 3H2O
note if w/NH3 then + 3NH4+

Question 14

Mn 2+ with NaOH

Answer 14

light brown ppt Mn(OH)2

darkens in air

Question 15

Cr 3+ with NaOH

Answer 15

grey-green ppt Cr(OH)3,

soluble in excess [Cr(OH)6]3-

Question 16

Cu 2+ with excess NH3

Answer 16

Deep blue solution

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

Question 17

Cr 3+ with excess NH3

Answer 17

Purple Solution

[Cr(NH3)6]3-

Question 18

Cu 2+ with conc. HCl

Answer 18

yellow solution

[CuCl4]2-