(a) Use the following reactions to arrange the elements A ,B, C and D in order of their redox reactivity : (i) A+B^(+) rarr A^(+) +B (ii) B+D^(+) rarr B^(+)D (iii) C^(+) +D rarr No reaction (iv) B+C^(+) rarrB^(+) C (b) On the basis of above redox activity series predict which of the following reactions would you expect to occur. (i) A^(+)CrarrA+C^(+)(ii) A^(+) +DrarrA+D^(+)

(a) Use the following reactions to arrange the elements A ,B, C and D

1.	(a) Use the following reactions to arrange the elements A ,B, C and D in order of their redox reactivity : (i) A+B^(+) rarr A^(+) +B (ii) B+D^(+) rarr B^(+)D (iii) C^(+) +D rarr No reaction (iv) B+C^(+) rarrB^(+) C (b) On the basis of above redox activity series predict which of the following reactions would you expect to occur. (i) A^(+)CrarrA+C^(+)(ii) A^(+) +DrarrA+D^(+)
Answer» Solution :(a) The electrochemical series or redox activity is BASED on the decreasing order of reduction POTENTIALS. This MEANS that the species which gets reduced is higher in the electrochemical series as compared to the other which is to get oxidised (lose electrons ) In reaction (i), `B^(+)` gets reduced by A and THEREFORE B is higher than A in electrochemical series. In reaction (ii) `D^+` gets reduced by B and therefore , D is higher in electrochemical series than B. In reaction (iii) `C^+` does not get reduced by D, therefore , C is lower than D in electrochemical series. But according to reaction (iv) `C^(+)` gets reduced by B and therefore , C is higher in electrochemical, series than B Thus , the correct order is `D gt C gt B gt A ` (b) Both reactions donot occur because A cannot be reduced by C as well as D.