question_answer

  (a) An iron nail is kept in copper sulphate solution. What happens and why? (b) A metal M does not liberate hydrogen from acids but reacts with oxygen to give a black colour product. Identify M and black coloured product and also explain the reaction of M with oxygen.

Answer:

  (a) If an iron nail is kept in CuSO4 solution, then iron nail gets brown coating due to Cu deposition and the? (1/2) Solution turns greenish due to the formation of FeSO4.                                                                                 (1/2) It is because, Fe being more reactive than Cu, displaces Cu from CuSO4 solution.                                               (1) (b) M is copper (Cu) as it is less reactive than hydrogen and gives. black product, copper oxide (CuO) with oxygen.                                                                                                                                                      (1/2)