Question 1

In which pair of species are the oxidation numbers of the d-block elements the same?

  A  

[Cr(NH3)4Cl2]+ and [Mn(H2O)6]2+


  B  

CrO42- and TiCl3

  C  

Cr2O3 and [Fe(CN)6]3-

  D  

Cr2O72- and MnO4-

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Question 2

The electronic configuration of the atoms of an element is 1s22s22p63s23p63d54s1.

What is the maximum oxidation number shown in compounds of this element?

  A  

+1

  B  

+5

  C  

+6

  D  

+7

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Question 3

Which of the following species will not act as a ligand in the formation of a complex ion?

  A  

CH3NH2

  B  

CN-

  C  

NH3

  D  

NH4+

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Question 4

Which has the greatest number of unpaired electrons in each of its atoms?

  A  

vanadium

  B  

chromium

  C  

manganese

  D  

iron

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Question 5

Which of these complex ions could exist as stereoisomers?

  A  

[Co(NH3)6]3+


  B  

[Co(NH3)5(H2O)]3+


  C  

[Co(NH3)5(Cl)]2+


  D  

[Co(NH3)4(Cl)2]+

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Question 6

Chromium is classified as a transition element because

  A  

it is in the d block of the periodic table

  B  

it forms stable ions in which it has different oxidation numbers

  C  

it has incompletely filled d orbitals

  D  

it forms stable ions which have incompletely filled d orbitals

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Question 7

Copper(II) sulfate solution is blue. This is because

  A  

excited electrons emit light in the blue region of the spectrum as they drop back to the ground state

  B  

excited electrons emit light in the red region of the spectrum as they drop back to the ground state

  C  

electrons absorb light in the red region of the spectrum and the residual  frequencies are observed

  D  

electrons absorb light in the blue region of the spectrum and the residual  frequencies are observed

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Question 8

Platinum forms a complex with the formula Pt(NH3)2Cl2 and chromium forms a complex ion with the formula CrCl4-.

Considering the bonding between the central atom and the ligands in these complexes,

  A  

the bonding in both complexes is dative covalent

  B  

the bonding in both complexes is ionic

  C  

the bonding in Pt(NH3)2Cl2 is dative covalent and in CrCl4- is ionic

  D  

the bonding in Pt(NH3)2Cl2 is ionic and in CrCl4- is dative covalent

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Question 9

The transition metal complex Pt(NH3)2Cl2 exists as two geometric isomers. This is because the complex

  A  

is square-planar

  B  

is tetrahedral

  C  

contains a double bond

  D  

is octahedral

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Question 10

Copper(II) ions form an aqueous complex ion, X, with chloride ions.

Which statement about X is true?

  A  

X has optical isomers 

  B  

X has a square planar shape


  C  

X has the formula CuCl42+

  D  

X has a yellow colour

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Question 11

What is the number of stereoisomers that Ni(H2NCH2CH2NH2)2Cl2 can form?

  A  

2

  B  

3

  C  

4

  D  

6

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Question 12

Which is not a correct statement?

  A  

transition metals form coloured ions and complexes

  B  

transition metals display variable oxidation states

  C  

a ligand accepts a pair of electrons from a transition metal

  D  

a complex is a central metal atom or ion surrounded by

ligands

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Question 13

A solution absorbs light with wavelengths corresponding to red, yellow and green light.

Which ion is most likely to be in the solution?

  A  

Cr2O72-(aq)

  B  

Fe2+(aq)

  C  

Fe3+(aq)

  D  

Cu2+(aq)

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Question 14

Which of the following reagents would enable you to separate iron(III) hydroxide from a mixture of iron(III) hydroxide and copper(II) hydroxide?

  A  

dilute hydrochloric acid

  B  

aqueous ammonia

  C  

dilute nitric acid

  D  

sodium hydroxide solution

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Question 15

The compound 1,2-diaminoethane, H2NCH2CH2NH2, is a bidentate ligand; in formulae, it is usually abbreviated to ‘en’.

When 1,2-diaminoethane is added to [Co(NH3)6]2+ in aqueous solution, [Co(en)3]2+ is formed.

What is the best explanation for this?

  A  

there are much stronger bonds between the ligands and the cobalt(II) ion in [Co(en)3]2+ than in [Co(NH3)6]2+

  B  

when [Co(en)3]2+ is formed from [Co(NH3)6]2+ the reaction is exothermic

  C  

when [Co(en)3]2+ is formed from [Co(NH3)6]2+ the total entropy change is positive

  D  

when [Co(en)3]2+ is formed from [Co(NH3)6]2+ the reaction has a low activation energy

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Question 16

The reaction:

[Fe(H2O)6]2+ + H2O ➔ [Fe(H2O)5(OH)]+ + H3O+

is an example of

  A  

oxidation

  B  

reduction

  C  

ligand exchange

  D  

acid-base behaviour

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Question 17

Hydrated crystals of a compound have the formula CrCl3(H2O)6.

A solution containing one mole of the compound reacts with two moles of silver nitrate to form two moles of silver chloride.

The complex chromium ion in the compound is most likely to be

  A  

[Cr(H2O)3Cl3]3+


  B  

[Cr(H2O)4Cl2]+


  C  

[Cr(H2O)5Cl]2+

  D  

[Cr(H2O)6]3+


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Question 18

What is the final species produced when an excess of aqueous ammonia is added to aqueous aluminium chloride?

  A  

[Al(NH3)6]3+


  B  

[Al(OH)3(H2O)3]

  C  

[Al(OH)4(H2O)2]-

  D  

[Al(OH)(H2O)5]2+

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