An excess of concentrated hydrochloric acid is added to separate aqueous solutions containing [Cu(H 2 O) 6 ] 2 and [Co(H 2 O) 6 ] 2.

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1 1 An exess of a given reagent is added to eah of the following pairs of aqueous metal ions. For eah metal ion, state the initial olour of the solution and the final oservation that you would make. In eah ase, write an overall equation for the formation of the final produt from the initial aqueous metal ion. a An exess of aqueous sodium aronate is added to separate aqueous solutions ontaining [Fe(H 2 O) 6 ] 2 and [Fe(H 2 O) 6 ] 3. (5 marks) An exess of onentrated hydrohlori aid is added to separate aqueous solutions ontaining [Cu(H 2 O) 6 ] 2 and [Co(H 2 O) 6 ] 2. An exess of dilute aqueous sodium hydroxide is added to separate aqueous solutions ontaining [Fe(H 2 O) 6 ] 2 and [Cr(H 2 O) 6 ] 3. d An exess of dilute aqueous ammonia is added to separate aqueous solutions ontaining [Al(H 2 O) 6 ] 3 and [Ag(H 2 O) 2 ]. AQA Chemistry, 2013, Unit 5 (Question 7) This resoure sheet may have een hanged from the original 1

2 2 This question is aout test-tue reations of some ions in an aqueous solution. For eah reation in parts a to d, state the olour of the original solution. State what you would oserve after the named reagent has een added to the solution. In eah ase, write an equation for the reation that ours. 2 a An exess of dilute sulfuri aid is added to a solution ontaining CrO ions. 4 Oservation after an exess of reagent has een added Sodium hydroxide solution is added to a solution ontaining [Fe(H 2 O) 6 ] 3 ions. Oservation after reagent has een added An exess of ammonia solution is added to a solution ontaining [Cu(H 2 O) 6 ] 2 ions. Oservation after an exess of reagent has een added This resoure sheet may have een hanged from the original 2

3 d Sodium aronate solution is added to a solution ontaining [Al(H 2 O) 6 ] 3 ions. Oservations after reagent has een added AQA Chemistry, 2013, Unit 5 (Question 5) 3 Aqueous metal ions an e identified y test-tue reations. For eah of the following, desrie what you would oserve. Write an equation or equations for any reations that our. a The addition of aqueous sodium aronate to a solution ontaining [Fe(H 2 O) 6 ] 3 (aq) ions. The addition of aqueous sodium hydroxide, dropwise until in exess, to a solution ontaining [Al(H 2 O) 6 ] 3 (aq) ions. The addition of dilute aqueous ammonia, dropwise until in exess, to a solution ontaining [Cu(H 2 O) 6 ] 2 (aq) ions. This resoure sheet may have een hanged from the original 3

4 d The addition of onentrated hydrohlori aid, dropwise until in exess, to a solution ontaining [Cu(H 2 O) 6 ] 2 (aq) ions. (2 marks) AQA Chemistry, 2011, Unit 5 (Question 6) 4 Hydrogen peroxide is used as an oxidising agent in the preparation of transition metal omplexes. a Consider the following reation sheme. All the omplexes are in aqueous solution. Reation 1 Reation 2 [Co(H 2 O) 6 ] 2 oalt(ii) omplex [Co(NH 3 ) 6 ] 3 H 2 O 2 i Identify a reagent for Reation 1 and desrie the olour hange that ours. ii State the olour of the final solution formed in Reation 2. (1 mark) Consider the following reation sheme. All the omplexes are in aqueous solution. i For Reation 3, state the olour of the initial and of the final solution and write an equation for the reation. This resoure sheet may have een hanged from the original 4

5 ii Write a half-equation for the redution of hydrogen peroxide to hydroxide ions. Dedue an overall equation for Reation 4 and state the olour of the final solution. The onentration of a hydrogen peroxide solution an e determined y titration with aidified potassium manganate(vii) solution. In this reation the hydrogen peroxide is oxidised to oxygen gas. A 5.00 m 3 sample of the hydrogen peroxide solution was added to a volumetri flask and made up to 250 m 3 of aqueous solution. A 25.0 m 3 sample of this diluted solution was aidified and reated ompletely with m 3 of mol dm 3 potassium manganate(vii) solution. Write an equation for the reation etween aidified potassium manganate(vii) solution and hydrogen peroxide. Use this equation and the results given to alulate a value for the onentration, in mol dm 3, of the original hydrogen peroxide solution. (If you have een unale to write an equation for this reation you may assume that 3 mol of KMnO 4 reat with 7 mol of H 2 O 2. This is not the orret reating ratio.) (5 marks) AQA Chemistry, 2011, Unit 5 (Question 7) This resoure sheet may have een hanged from the original 5

6 5 a State what is oserved when aqueous ammonia is added dropwise, until present in exess, to a solution of oalt(ii) hloride, and the mixture otained is then left to stand in air. Give the formula of eah oalt-ontaining speies formed. Explain the hange whih ours when the mixture is left to stand in air. (8 marks) Explain why separate solutions of iron(ii) sulfate and iron(iii) sulfate of equal onentration have different ph values. State what is oserved when sodium aronate is added separately to solutions of these two ompounds. Give the formula of eah iron-ontaining speies formed. (9 marks) AQA Chemistry, 2003, Unit 5 (Question 6) This resoure sheet may have een hanged from the original 6

Oxide Q is a colourless gas at room temperature. It dissolves in water to give a solution with a low ph.

Oxide Q is a colourless gas at room temperature. It dissolves in water to give a solution with a low ph. Q1. (a) P and Q are oxides of Period 3 elements. Oxide P is a solid with a high melting point. It does not conduct electricity when solid but does conduct when molten or when dissolved in water. Oxide