Periodicity Of The D Block

Question 1

What’s the order of transition metals left to right?

Answer 1

Titanium
Vanadium
Chromium
Manganese
Iron
Cobalt
Nickel
Copper

Question 2

What is the highest attainable oxidation state of series 1 TMs?

Answer 2

Reaches a peak at Mn(VII) - then decreases as Zeff increases

Question 3

What’s the most common oxidation state of Ti?

Answer 3

4+

Question 4

Why does Ti(II) not exist for long?

Answer 4

Because it is strongly reducing, d2 metal ion

Question 5

Which 1st series TM ion is oxidising in solution?

Answer 5

Vanadium(V)

Becomes V(IV) - most common

Question 6

What’s the most common oxidation state of V?

Answer 6

V(IV)

Question 7

What’s the most common oxidation state of Cr?

Answer 7

Cr(III)

Question 8

What’s the most common oxidation state of Mn?

Answer 8

Mn(II)

Question 9

What’s the most common oxidation state of Fe?

Answer 9

Fe(II) and Fe(III)

Question 10

What’s the most common oxidation state of Co?

Answer 10

Co(II) and Co(III)

Question 11

What’s the most common oxidation state of Ni?

Answer 11

Ni(II)

Question 12

What’s the most common oxidation state of Cu?

Answer 12

Cu(I) and Cu(II)

Question 13

What properties do Cr(VI) and Mn(VII) exhibit?

Answer 13

Strong oxidising agents - often used in organic chemistry (CrO3) oxidise alcohols and ([MnO4]-) methyl units to carb. acids.

Question 14

How is Fe(VI) made, what is its structure?

Answer 14

Made by IO4- oxidation of Fe(III) in pH 14 solution

Only one complex, [FeO4]2- (tetrahedral)

Question 15

Why is it very rare to attain Co(IV)?

Answer 15

Because Co(III) is low-spin d6 which is hard to disrupt due to its stability

Question 16

Why is nickel’s highest oxidation state Ni(IV)?

Answer 16

Because it is a low-spin d6 metal ion - gaining stability, more common than Co(IV)

Question 17

What is the highest oxidation state of Cu?

Answer 17

Cu(III) a d8 metal ion - due to steric and electronic repulsions

Question 18

What’re common properties of Copper complexes?

Answer 18

Most are diamagnetic, square planar complexes

Question 19

Which is more stable, Cu(I) or Cu(II)?

Answer 19

Cu(I) - as it is a d10 metal ion

Cu(II) is a d9 metal ion and hence is less stable than d10

There are still many complexes of both however…

Question 20

What is the trend of the energy required to ionise a metal to 2+ of the 1st series TMs?

Answer 20

There is a general increase from Sc to Zn

Though Fe is considerably lower since Fe(II) is d6 and hence stable

Question 21

What’re generalisations about 4d/5d metals?

Answer 21

Higher oxidation states are more common and more stable than 3d metals

4d/5d metals are very similar to each other - due to Lanthanide contraction - but differ from 3d metal in group.

Question 22

What are the main differences between Cr(VI) with Mo(VI) and W(VI)?

Answer 22

Cr(IV) is strongly oxidising whereas Mo(VI) and W(VI) are barely oxidising at all

(They form ionic lattices with MO3 and MO6 units)

Question 23

Answer 23

[ReO4]- is quite inert - used as inert anion when cations are unstable

Whereas [MnO4]- is strongly oxidising

Question 24

Compare high oxidation state oxides of Fe, Ru and Os

Answer 24

[FeO4]2- is Fe(VI)

But RuO4 and OsO4 are both M(VIII) - 4d/5d metal can accommodate higher oxidation state - d0 complexes

Question 25

Compare high oxidation states of Co with Rh and Ir

Answer 25

[CoF6]2- is Co(IV) d5 metal complex

But RhF6 and IrF6 are both M(VI) - d3 metal complexes

Question 26

Compare high oxidation states of Ni, Pd and Pt

Answer 26

Pd is actually like Ni, with same highest oxidation state of M(IV)

Pt gives [PtF6] and [PtF6]- as well, higher oxidation state - 5/6+

100% exam

Question 27

What’s the trend down the groups of transition metal ions?

Answer 27

3d metal ions are much smaller than 4d/5d metal ions of same oxidation

However 4d/5d are much the same size, this is due to the Lanthanide construction - 4f orbital is laughably bad at shielding from the core.

Question 28

What is the order of oxidising agents from W to Pt?

Answer 28

Pt is most oxidising

W is least oxidising