General physical and chemical properties of the first row of transition elements, titanium to copper — Paper 1 · A Level Chemistry 9701

9 When copper is extracted from its ores, the metal is not pure enough for electrical uses. The impure copper, which contains small amounts of silver and gold, is purified by electrolysis. During this process a ‘sludge’ forms beneath the anode which is found to contain silver and traces of gold. Why is silver found in this sludge? A Silver is less electropositive than copper. B Silver is more dense than copper and falls off the cathode. C Silver reacts with the electrolyte to form an insoluble chloride salt. D Silver reacts with the electrolyte to form an insoluble sulfate salt.

1 marks

Answer: A

This question in 9701/11 May/June 2009

32 Zirconium, Zr, proton number 40, is a metal which is used in corrosion-resistant alloys. Zirconium metal is extracted from the oxide ZrO2 by the following sequence of reactions. reaction 1 ZrO2 + 2Cl 2 + 2C → ZrCl 4 + 2CO reaction 2 ZrCl 4 + 2Mg → Zr + 2MgCl 2 Which statements about this extraction process are correct? 1 Carbon in reaction 1 behaves as a reducing agent. 2 Magnesium in reaction 2 behaves as a reducing agent. 3 Chlorine in reaction 1 behaves as a reducing agent.

1 marks

Answer: B

This question in 9701/12 Oct/Nov 2010

17 In the Haber process, the reaction between the two gaseous reactants requires the use of a catalyst that contains a transition element. What is the metal and in what mole ratio do the gases react? metal mole ratio A Fe 1 : 2 B Fe 1 : 3 C V 1 : 2 D V 1 : 3

1 marks

Answer: B

This question in 9701/13 Oct/Nov 2012

1 Use of the Data Booklet is relevant to this question. Atoms of element X have six unpaired electrons. What could be element X? A carbon B chromium C iron D selenium

1 marks

Answer: B

This question in 9701/11 May/June 2014

31 Use of the Data Booklet is relevant to this question. Which ions contain one or more unpaired electrons? 1 Cu2+ 2 Mn3+ 3 V3+

1 marks

Answer: A

This question in 9701/12 Oct/Nov 2014

35 Water is added to anhydrous aluminium chloride to make a 0.1 mol dm–3 solution. Which observations are correct? 1 The reaction is endothermic. 2 The solution is acidic. 3 The solution contains the ion [Al (H2O)6]3+.

1 marks

Answer: C

This question in 9701/11 Oct/Nov 2016

31 An isolated gaseous atom of element X has paired electrons in at least one of its 3d orbitals and has a filled 4s subshell. What could be the identity of element X? 1 iron 2 gallium 3 copper

1 marks

Answer: B

This question in 9701/12 May/June 2017

33 Aqueous iron(II) sulfate can take part in redox reactions. 6FeSO4 + 7H2SO4 + Na2Cr2O7 → 3Fe2(SO4)3 + Cr2(SO4)3 + Na2SO4 + 7H2O Which redox changes occur during this reaction? 1 Fe(II) is oxidised to Fe(III). 2 Cr(VI) is reduced to Cr(III). 3 Oxygen is reduced to water.

1 marks

Answer: B

This question in 9701/12 Oct/Nov 2018

31 Which ions contain one or more unpaired electrons? 1 Cu2+ 2 Mn3+ 3 V3+

1 marks

Answer: A

This question in 9701/13 Oct/Nov 2018

2 Cobalt can form the positive ion Co(NH3)4Cl 2 +. What is the oxidation number of cobalt in this ion? A +1 B +2 C +3 D +6

1 marks

Answer: C

This question in 9701/11 May/June 2020

10 In which pair does each species have the same number of unpaired electrons? A Al and Cu2+ B Ca and Cr3+ C Ca and Ni2+ D Fe3+ and O2–

1 marks

Answer: A

This question in 9701/11 May/June 2020

8 What is the electronic configuration of an isolated Ni2+ ion? A 1s22s22p63s23p63d64s2 B 1s22s22p63s23p63d74s1 C 1s22s22p63s23p63d104s2 D 1s22s22p63s23p63d8

1 marks

Answer: D

This question in 9701/13 May/June 2020

3 Technetium (Tc) is a second row transition element that does not occur naturally on Earth. One of its isotopes has 56 neutrons. What is the nucleon number of this isotope? A 43 B 56 C 99 D 112

1 marks

Answer: C

This question in 9701/12 Oct/Nov 2021

13 The equation for the reaction between aqueous copper ions and aqueous iodide ions is as follows. 2Cu2+(aq) + 4I–(aq) →2CuI(s) + I2(aq) What is the change in oxidation state of copper? A +2 to –1 B +2 to 0 C +2 to +1 D +4 to +2

1 marks

Answer: C

This question in 9701/12 Oct/Nov 2023

14 Photochromic glass, used for sunglasses, darkens when exposed to bright light and becomes more transparent again when the light is less bright. The darkness of the glass is due to the presence of silver atoms. The following reactions are involved. reaction 1 Ag+ + Cl– Ag + Cl reaction 2 Cu+ + Cl Cu2+ + Cl– reaction 3 Cu2+ + Ag  Cu+ + Ag+ Which statement about these reactions is correct? A Cu+ and Cu2+ ions act as catalysts. B Cu+ ions act as an oxidising agent in reaction 2. C Reaction 3 increases the darkness of the glass. D Silver atoms are reduced in reaction 3.

1 marks

Answer: A

This question in 9701/13 Oct/Nov 2025