Q1.In the table below, which one of the following complex ions has a correct shape, co-ordination number and oxidation state?
 
 	 	Complex	Shape	Co-ordination
number	Oxidation state of
central cation	
 	A	[Ag(CN)2]−	Linear	2	–1	
 	B	[CuCl4]2−	Tetrahedral	4	–2	
 	C	[Cr(C2O4)3]3−	Octahedral	3	+3	
 	D	[Cu(NH3)4(H2O)2]2+	Octahedral	6	+2	

(Total 1 mark)

Q2.(a)     Explain how the electron pair repulsion theory can be used to deduce the shape of, and the bond angle in, PF3
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(6)
(b)     State the full electron configuration of a cobalt(II) ion.
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(1)

(c)     Suggest one reason why electron pair repulsion theory cannot be used to predict the shape of the [CoCl4]2− ion.
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(1)

(d)     Predict the shape of, and the bond angle in, the complex rhodium ion [RhCl4]2−.
Shape ............................................................................................................
Bond angle .....................................................................................................
(2)
(Total 10 marks)
Q3.          Transition metals and their complexes have characteristic properties.
(a)     Give the electron configuration of the Zn2+ ion.
Use your answer to explain why the Zn2+ ion is not classified as a transition metal ion.
Electron configuration ..................................................................................
Explanation ..................................................................................................
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(2)
(b)     In terms of bonding, explain the meaning of the term complex.
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(2)
(c)     Identify one species from the following list that does not act as a ligand. Explain your answer.
H2          O2–          O2          CO
Not a ligand..................................................................................................
Explanation ...................................................................................................
(2)

(d)     The element palladium is in the d block of the Periodic Table. Consider the following palladium compound which contains the sulfate ion.
[Pd(NH3)4]SO4
(i)      Give the oxidation state of palladium in this compound.
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(1)

(ii)     Give the names of two possible shapes for the complex palladium ion in this 
compound.
Shape 1 ..............................................................................................
Shape 2 ..............................................................................................
(2)
(Total 9 marks)

M1.D
[1]
M2.(a)     This question is marked using levels of response. Refer to the Mark Scheme Instructions for Examiners for guidance on how to mark this question.
All stages are covered and the explanation of each stage is generally correct and virtually complete.
Answer is communicated coherently and shows a logical progression from stage 1 to stage 2 then stage 3.
Level 3
5 – 6 marks
All stages are covered but the explanation of each stage may be incomplete or may contain inaccuracies OR two stages are covered and the explanations are generally correct and virtually complete.
Answer is mainly coherent and shows progression from stage 1 to stage 3.
Level 2
3 – 4 marks
Two stages are covered but the explanation of each stage may be incomplete or may contain inaccuracies, OR only one stage is covered but the explanation is generally correct and virtually complete
Answer includes isolated statements but these are not presented in a logical order or show confused reasoning.
Level 1
1 – 2 marks
Insufficient correct chemistry to gain a mark.
Level 0
0 marks
Indicative chemistry content
Stage 1: Electrons round P
•        P has 5 electrons in the outside shell
•        With 3 electrons from 3 fluorine, there are a total of 8 electrons in outside shell
•        so 3 bond pairs, 1 non-bond pair
Stage 2: Electron pair repulsion theory
•        Electron pairs repel as far as possible
•        Lone pair repels more than bonding pairs
Stage 3: Conclusions
•        Therefore, tetrahedral / trigonal pyramidal shape
•        With angle of 109(.5)° decreased to 107°
6
(b)     1s22s22p63s23p63d7
Allow correct numbers that are not superscripted
1
(c)     Too many electrons in d sub-shell / orbitals
1

(d)     Tetrahedral (shape)
1
109.5°
Allow 109°
1
[10]
M3.          (a)     1s2 2s2 2p6 3s2 3p6 3d10
allow [He] 2s2 . or [Ne] 3s2.or [Ar]3d10
1
d sub-shell / shell / orbitals / sub-level full (or not partially full)
can only score M2 if d10 in M1 correct
allow ‘full d orbital’ if d10 in M1
do not allow d block
1
(b)     atom or ion or transition metal bonded to / surrounded by
one or more ligands
Allow Lewis base instead of ligand
1
by co–ordinate / dative (covalent) bonds / donation of
an electron pair
can only score M2 if M1 correct
1
(c)     H2 / hydrogen
do not allow H
1
no lone / spare / non-bonded pair of electrons
only score M2 if M1 correct or give ‘H’ in M1
1

(d)     (i)      +2 or 2+ or Pd2+ or II or +II or II+ or two or two plus
1
(ii)     tetrahedral
these shapes can be in any order
1
square planar
allow phonetic spelling e.g. tetrahydral
1
[9]