question_answer

  What happens when zinc granules are treated with dilute solution of H2SO4, HCl, HNO3, Nad and NaOH? Also write the chemical equations if reaction occurs.                                                                                  [NCERT Exemplar]

Answer:

                  The reaction of Zn granules with (i) dilute H2SO4                  Zn(s) + H2SO4(aq)  ZnSO4(aq) + H2(g) (ii) dilute HCl                 Zn(s) + 2HCl(aq)    ZnCl2(aq) + H2(g)                 (iii) dilute HNO3 Reaction with dilute HNOg is different as compared to other acids because nitric acid is an oxidizing agent and it oxidizes Hg gas evolved to H2O. 4Zn(s) + 10HNO3(aq)  4Zn(NO3)2(aq) + 5H2O(l) + N2O(g) (iv) NaCI solution                 Zn(s) + NaCl(aq)  No reaction (v)    NaOH solution Zn(s) + 2NaOH(aq)  Na2ZnO2(aq)+H2(g)                                                                 Sodium zincate