Question

Out of three metals P, Q and R, P is less reactive than Q and R is more reactive than P and Q both. Suggest an activity to arragne P, Q and R in order of their decreasing reactivity. 

Answer 1

Step-1 : Salt solutions of metal P,Q and R were taken 

Step-2 : Since, according to question P < Q < R 

Since R is more reactive than Q and P so displacement reaction will take place.

(I) R + salt of Q → salts of R + Q
   (s)       (aq)             (aq)         (s)

  R + salt of P → salts of R + P
  (s)      (aq)            (aq)       (s)

(II) Q + salt of R → No reaction
     (s)       (aq)   

    Q + salt of P→ salts of Q +  P
   (s)       (aq)             (aq)         (s)  

(III) P + salt of R → No reaction
     (s)       (aq)   

     P + salt of Q → No reaction
     (s)       (aq)