Transition metals

Question 1

What is a transition metal

Answer 1

d block element with partially filled d orbitals

Question 2

4 properties of transition metal

Answer 2

-complexes
-coloured ions
-variable oxidation states
-catalysts

Question 3

Ligand?

Answer 3

Molecules or ions with lone electron pairs forming a coordinate bond with central metal atom

Question 4

what happens with copper and NH3 in excess

Answer 4

incomplete ligand substitution (4)

Deep blue

Question 5

Bidentate? and 2 types

Answer 5

Can form 2 coordinate bonds

ethandioate (C2O4-)

ethane-1,2-diamine (NH2CH2CH2NH2)

Question 6

Multidentate? example

Answer 6

Can form 6 coodrinate bonds

EDTA(4-)

e.g heam (link to carbon monoxide poisoning)

Question 7

What is the chelate effect?

Answer 7

Unidentate ligands are substituted for bidentate or multidentae = a positive entropy change

so gibbs free energy is more negative, so more favourable and stable

Question 8

Enthalpy change?

Answer 8

near zero as bonds being formed are very simlar to bonds being broken

Question 9

Octahedral?

Answer 9

H2O or NH3

90 degrees

cis/trans isomerism

or optical if bidentate

Question 10

Tetrahedral?

Answer 10

Cl-

(larger ion)

109.5 degrees

optical

Question 11

Square planar?

Answer 11

platnum and nickel

90 degrees

cis trans

Question 12

Linear?

Answer 12

silver

180 degrees

e.g tollens

Question 13

Why coloured?

Answer 13

Electrons in partially filled orbitals

can get excited form ground state to a higher energy state

this energy change corresponds to a wavelenth of light and absorbance

Question 14

Oxidation states?

Answer 14

Vanadium

5- yellow
4-blue
3-green
3-purple

Question 15

Catalysts?

Answer 15

Homogeneous:
same phase
two negative ions or autocatalysis

Hetrogeneous:
different phase
haber process
adsorption