Edexcel Jan 2017 (IAL) Paper 5 Q18

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17 Copper(II) ions oxidise titanium(II) ions. The relevant half-equations are Half-equation 1 Ti3+ + e (cid:85) Ti2+ Half-equation 2 Cu2+ + 2e (cid:85) Cu E(cid:57) = +0.34 V E(cid:57) cell for the reaction = + 0.71 V. The standard electrode potential for half-equation 1 is A 0.37 V B 1.05 V C +0.37 V D +1.05 V (Total for Question 17 = 1 mark) 18 This question is about the following reactions. 2Fe2+(aq) + Br2(aq) (cid:111) 2Fe3+(aq) + 2Br(aq) 2Fe2+(aq) + I2(aq) (cid:111) 2Fe3+(aq) + 2I(aq) 2Fe3+(aq) + 2Br(aq) (cid:111) 2Fe2+(aq) + Br2(aq) 2Fe3+(aq) + 2I(aq) (cid:111) 2Fe2+(aq) + I2(aq) Relevant standard electrode potentials are shown in the table. Electrode reaction I2(aq) + 2e (cid:85) 2I(aq) 2Fe3+(aq) + 2e (cid:85)(cid:3)(cid:3)2Fe2+(aq) Br2(aq) + 2e (cid:85) 2Br(aq) E(cid:57)/V +0.54 +0.77 +1.09 Which reactions are thermodynamically feasible under standard conditions? P and Q B P and S C Q and R D Q and S (Total for Question 18 = 1 mark) A E R A S I H T N I E T I R W T O N O D A E R A S I H T N I E T I R W T O N O D A E R A S I H T N I E T I R W T O N O D *P48373A0732* Turn over<br />

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