Topic 10: Ligand Exchange and Stability in d-Block Complexes

Question 1

Most d-block metals react with acids to …
The metal is … which is …

Answer 1

liberate H2 and form a metal salt
oxidised
favourable

Question 2

delta G (J) =

Answer 2

-nFE
n = moles of electrons transferred per mole of reaction
F = 96485 C mol^-1 (Faradays Constant)
E = Energy (V)

-(RT)lnK

Question 3

Requirements for a thermodynamically favourable reaction

Answer 3

For the overall reaction
E > 0
G < 0

Question 4

Strongly polarising, metal-aqua cations readily … to form …
As the metals charge increases, … so … may be lost to produce a …

Answer 4

lose a proton
an acidic solution and a Metal-Hydroxide species
It becomes even more polarising and 2 protons may be lost
Oxide ligand

Question 5

hydroxide and oxo ligands can lead to …which have higher …

Answer 5

hydroxy and oxo bridged species
nuclearity

Question 6

Solvated metal cations will react with … to replace the … but sometimes …

Answer 6

other donor ligands
co-ordinated water ligands
not all water ligands are displaced

Question 7

… charged ligands are required around a central metal ion than neutral ligands.

Answer 7

fewer

Question 8

1st row transition metals coordinated to chloride or iodide ions tend to be … due to …

Answer 8

tetrahedral
packing (space around metal)

Question 9

K1 (equilibrium constant) =
K2 =
K3 =

Answer 9

[M(L)(H2O)5]^n+/[M(H2O)6]^n+[L]
[M(L)2(H2O)4]^n+/[M(L)(H2O)5]^n+[L]
etc

Question 10

beta 6 =
beta 2 =

Answer 10

K1 x K2 x K3 x K4 x K5 x K6
K1 x K2

Question 11

log beta 6 =

Answer 11

logK1 + logK2 + logK3 + logK4 + logK5 + logK6

Question 12

Trend in Km is … but can deviate due to …

Answer 12

K1 > K2 … >K6
changes in geometry or Jahn-Teller effects

Question 13

Why does the value of K1 to K6 steadily decrease for ammonia complexes

Answer 13

The ammonia ligand can replace another ammonia ligand instead of a. H2O (fewer water molecules to replace)