1 General properties

Found it useful? Your friends might too!

 

/
~
~
~
/
Show Learning Materials


Oxford Textbook Pages : 358 - 359

CGP Revision Guide Pages : 108 - 109

/
/
/
/

Show Specification Ref : 3.2.5.1

/
/
/
/
Show past exam questions

Question 1 / 5

January 2010 QP – Unit 5 AQA Chemistry A-level_question_9 areas outside the box will not be scanned for marking a state the electron configuration of a ti iii ion and that of a ti iv ion explain in terms of electron configurations and electron transitions why ti iii compounds are usually coloured but ti iv compounds are colourless marks extra space question continues on the next page turn over wmp jan chem areas outside the box will not be scanned for marking b transition metal ions and their complexes can often be identified from their colours for each of the following identify a complex ion responsible for the colour of the aqueous solution restrict your answers to complexes formed from the elements cr fe co and cu a deep blue solution formed in an excess of concentrated aqueous ammonia a green solution formed in an excess of aqueous sodium hydroxide a yellow green solution formed in an excess of concentrated hydrochloric acid marks c an experiment is carried out to investigate the rate of the autocatalysed reaction between aqueous potassium manganate vii and ethanedioate ions in an excess of dilute sulfuric acid when these reagents are mixed together the colour of the reaction mixture gradually fades the concentration of the manganate vii ions is recorded at different times using a spectrometer the temperature of the reaction mixture is constant c i give two reasons why the use of a spectrometer is the most appropriate method for measuring the concentration of the coloured ions in this experiment marks extra space wmp jan chem areas outside the box will not be scanned for marking c ii sketch a curve to show how you would expect the concentration of manganate vii ions to change with time until the colour has faded because the concentration has reached a very low value explain the shape of the curve marks extra space end of questions wmp jan chem
Show answer

Question 2 / 5

January 2011 QP – Unit 5 AQA Chemistry A-level_question_4 do not write outside the box three characteristic properties of transition metals are complex formation coloured ions and catalytic activity a state the feature of transition metals that gives rise to these characteristic properties mark b state a fourth characteristic property of transition metals mark c for each of the following shapes of complex identify an appropriate example by drawing its structure c i a linear complex c ii a square planar complex c iii a tetrahedral complex question continues on the next page mark mark mark turn over wmp jan chem do not write outside the box d the chemical industry makes use of the catalytic activity of transition metal compounds for example vanadium v oxide is used as a heterogeneous catalyst in the contact process d i write an equation for the overall reaction in the contact process mark d ii explain the meaning of the term heterogeneous as applied to a catalyst mark d iii write two equations to illustrate how vanadium v oxide acts as a catalyst in the contact process equation equation marks d iv suggest what is done to a heterogeneous catalyst such as vanadium v oxide to maximise its efficiency and how this is achieved marks wmp jan chem do not write outside the box e the porphyrin ring is a multidentate ligand that is found in living systems complexed with iron ii ions in haemoglobin and with cobalt ii ions in vitamin b e i give the meaning of the term multidentate mark e ii a porphyrin ring can be represented by the symbol pr it reacts with aqueous iron ii ions as shown in the equation below the enthalpy change for this reaction is approximately zero pr aq fe h o aq fepr h o aq h o i explain why the free energy change for this reaction is negative marks e iii in vitamin b the cobalt ii ion is co ordinated to a porphyrin ring a cyanide cn ion and an additional unidentate ligand the cyanide ion is very toxic predict the co ordination number of the cobalt ion in vitamin b suggest why vitamin b is not toxic co ordination number reason why vitamin b is not toxic marks turn over wmp jan chem
Show answer

Question 3 / 5

January 2012 QP – Unit 5 AQA Chemistry A-level_question_7 section b answer all questions in the spaces provided do not write outside the box a due to their electron arrangements transition metals have characteristic properties including catalytic action and the formation of complexes with different shapes give two other characteristic properties of transition metals for each property illustrate your answer with a transition metal of your choice marks b other than octahedral there are several different shapes shown by transition metal complexes name three of these shapes and for each one give the formula of a complex with that shape marks wmp jan chem do not write outside the box c it is possible for group metal ions to form complexes for example the ca h o ion in hard water reacts with edta ions to form a complex ion in a similar manner to hydrated transition metal ions this reaction can be used in a titration to measure the concentration of calcium ions in hard water c i write an equation for the equilibrium that is established when hydrated calcium ions react with edta ions mark c ii explain why the equilibrium in part c i is displaced almost completely to the right to form the edta complex marks c iii in a titration cm of a mol dm solution of edta reacted completely with the calcium ions in a cm sample of a saturated solution of calcium hydroxide calculate the mass of calcium hydroxide that was dissolved in dm of the calcium hydroxide solution marks extra space turn over wmp jan chem
Show answer

Question 4 / 5

June 2010 QP – Unit 5 AQA Chemistry A-level_question_5 do not write outside the box the scheme below shows some reactions of copper ii ions in aqueous solution w x y and z are all copper containing species concentrated hcl scrap iron cu s cu h o aq dilute nh aq an excess of nh aq na co aq a identify ion w describe its appearance and write an equation for its formation from cu h o aq ions ion w appearance equation marks b identify compound x describe its appearance and write an equation for its formation from cu h o aq ions compound x appearance equation marks wmp jun chem do not write outside the box c identify ion y describe its appearance and write an equation for its formation from x ion y appearance equation marks d identify compound z describe its appearance and write an equation for its formation from cu h o aq ions compound z appearance equation marks e copper metal can be extracted from a dilute aqueous solution containing copper ii ions using scrap iron e i write an equation for this reaction and give the colours of the initial and final aqueous solutions equation initial colour final colour marks e ii this method of copper extraction uses scrap iron give two other reasons why this method of copper extraction is more environmentally friendly than reduction of copper oxide by carbon reason reason marks turn over wmp jun chem
Show answer

Question 5 / 5

June 2013 QP – Unit 5 AQA Chemistry A-level_question_7 section b answer all questions in the spaces provided do not write outside the box an excess of a given reagent is added to each of the following pairs of aqueous metal ions for each metal ion state the initial colour of the solution and the final observation that you would make in each case write an overall equation for the formation of the final product from the initial aqueous metal ion a an excess of aqueous sodium carbonate is added to separate aqueous solutions containing fe h o and fe h o marks b an excess of concentrated hydrochloric acid is added to separate aqueous solutions containing cu h o and co h o marks wmp jun chem do not write outside the box c an excess of dilute aqueous sodium hydroxide is added to separate aqueous solutions containing fe h o and cr h o marks d an excess of dilute aqueous ammonia is added to separate aqueous solutions containing al h o and ag h o marks turn over for the next question turn over wmp jun chem
Show answer
/
/
/
/
/
/