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OCR Chemistry A > Transition Elements > Flashcards

Flashcards in Transition Elements Deck (18)
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1
Q

True transition metal definition

A

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

2
Q

Ligand definition

A

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

3
Q

Coordination number

A

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

4
Q

EDTA 4- use

A

Forms 6 coordinate bonds

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

5
Q

Use of cis-platin

A

Important anti-cancer drug- prevents cell division

6
Q

Cu 2+ solution colour

A

Pale blue

7
Q

Fe 2+ solution colour

A

pale green

8
Q

Fe 3+ solution colour

A

pale yellow

9
Q

Mn 2+ solution colour

A

pale pink

10
Q

Cr 3+ solution colour

A

pale purple

in presence of H2SO4 = green solution

11
Q

Cu 2+ with NaOH

A

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+

12
Q

Fe 2+ with NaOH

A

green ppt Fe(OH)2

oxidises to brown in air Fe(OH)3

13
Q

Fe 3+ with NaOH

A

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+

14
Q

Mn 2+ with NaOH

A

light brown ppt Mn(OH)2

darkens in air

15
Q

Cr 3+ with NaOH

A

grey-green ppt Cr(OH)3,

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

16
Q

Cu 2+ with excess NH3

A

Deep blue solution

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

17
Q

Cr 3+ with excess NH3

A

Purple Solution

[Cr(NH3)6]3-

18
Q

Cu 2+ with conc. HCl

A

yellow solution

[CuCl4]2-