Transition Metals

Question 1

D block elements properties

Answer 1

All metallic, so have high melting and boiling points, shiny in appearance and conduct electricity and heat.
Copper, silver, nickel and zinc have been used in coinage.
Iron used in construction and production of tools.
Copper used in electrical cables and water pipes.
Titanium has great strength and is used in aerospace industry and medical applications eg joint replacement.

Question 2

When forming an atom the 4s orbital….

When forming an ion the 4s orbital….

Answer 2

Fills before the 3d orbitals.

Empties before the 3d orbitals.

Question 3

A species containing a transition element in its highest oxidation state

Answer 3

Is often a strong oxidant agent.

Question 4

Iron 2+ and iron 3+ ions electron configurations and colours

Answer 4

Iron (II) ion: Fe2+ 1s2 2s2 2p6 3s2 3p6 3d6 -pale green

Iron (III) ion: 1s2 2s2 2p6 3s2 3p6 3d10 - yellow

Question 5

The contact process

Answer 5

Production of sulcus trioxide from oxidation of sulfur dioxide. Reaction catalysed by vanadium oxide V2O5
2SO2 (g) + O2 (g) -> 2SO3 (g)

Question 6

Decomposition of hydrogen peroxide

Answer 6

2H2O2 (aq) -> 2H2O (l) + O2 (g)

Question 7

Fe2+ catalyst in reaction between S2O8 2- and Fe 2+

Answer 7

S2O8 2- (aq) +Fe2+ (aq) -> 2SO4 2- (aq) + Fe3+ (aq)

Fe3+ (aq) + 2I- (aq) -> I2 (aq) + Fe2+ (aq)

Question 8

Bidentate ligands

Answer 8

These ligands can donate two lone pairs of electrons to the central metal ion, forming two coordinate bonds.

Question 9

Most common ligands

Answer 9

See card 1

Question 10

Octahedral shape and bond angle

Answer 10

90 degrees

See card 2

Question 11

Tetrahedral shape and bond angle

Answer 11

109.5 degrees

See card 3

Question 12

Square planar shape and bond angle

Answer 12

Platinum (II) and palladium (II) and gold (III) and tend to form square planar shapes.
90 degrees
See card 4

Question 13

In the cis isomer the bond angle between identical ligands are..
In trans isomer the coordinate bonds between the identical ligands are..

Answer 13

90 degrees

180 degrees

Question 14

Do cis or trans isomers form optical isomers

Answer 14

Cis, trans cannot form optical isomers as mirror image is exactly same and can be superimposed.

Question 15

Two different reactions of ligand substitution of Cu with ammonia

Answer 15

Pale blue precipitate of Cu(OH)2 is formed in the first stage of the reaction. 
The Cu(OH)2 precipitate then dissolves in excess ammonia to form a dark blue solution.

Question 16

Ligand substitution with chloride ions

Answer 16

Conc HCL added to [Cu(H2O)6]2+ pale blue solution becomes yellow.
If water added to yellow solution, blue solution formed (more dilute and paler in colour than original blue solution).
Intermediate is green solution (result of yellow mixing with blue)
See card 5

Question 17

Chromium potassium sulfate also known as

Answer 17

Chrome alum

Question 18

Reaction of [Cr(H2O)6]3+ with ammonia equation

Answer 18

See card 6

Question 19

Carbon monoxide and ligand substitution

Answer 19

Can bind to Fe2+ ion in haem, called carboxyhaemoglobin.
If CO breathed in, ligand substitution takes place where oxygen in haemoglobin replaces by CO.
Bond is so strong that process is irreversible, if conc of carboxyhaemoglobin becomes too high, O2 transport is prevented leading to death.

Question 20

Transition metal ions in aq solution react with

Answer 20

Aq sodium hydroxide and aq ammonia to form precipitates.

Some of these precipitates dissolve in excess NaOH or NH3 to form complex ions in solution.

Question 21

Cu2+ reaction equation with NaOH

Answer 21

See card 7

Question 22

Fe2+ reaction with NaOH

Answer 22

Pale green solution reacts to form green precipitate.
Precipitate insoluble in excess NaOH but turns brown at surface on standing in air as iron (II) is oxidised to iron (III)
See card 8

Question 23

Reaction of Fe3+ with NaOH

Answer 23

Pale yellow solution reacts to form an orange-brown precipitate of iron (III) hydroxide. Precipitate insoluble in excess NaOH
See card 9

Question 24

Reaction of Mn2+ with NaOH

Answer 24

Pale pink solution reacts to form light brown precipitate of manganese hydroxide which darkens on standing in air. Precipitate is insoluble in excess NaOH.
See card 10

Question 25

Cr3+ with NaOH

Answer 25

Violet solution reacts to form a grey green precipitate of chromium (III) hydroxide.
Precipitate is soluble in excess NaOH forming a dark green solution.
See card 11

Question 26

Redox reaction involving transition metal Fe2+ and Mn

Answer 26

See card 12

Question 27

Reduction of Fe3+ to Fe2+

Answer 27

See card 13

Question 28

Reaction of dichromate and chromium

Answer 28

See card 14

Question 29

Oxidation of Cr3+ to CrO4 2-

Answer 29

See card 15

Question 30

Reduction of Cu2+ to Cu+

Answer 30

See card 16

Question 31

Disproportionation of Cu+ ions

Answer 31

See card 17

Question 32

Identifying ammonium ions

Answer 32

See card 18
Test for ammonium ion ; aq NaOH heated gently with solution. If ammonia evolved damp red pH indicator paper will turn blue.