question_answer 77)

  When liquid 'A' is treated with a freshly prepared ammonia cal silver nitrate solution, it gives bright silver mirror. The liquid forms a white crystalline solid on treatment with sodium hydrogensulphite. Liquid 'B' also forms a white crystalline solid with sodium hydrogensulphite but it does not give test with ammonia cal silver nitrate. Which of the two liquids is aldehyde ? Write the chemical equations of these reactions also.  

Answer:

                  (i) Since liquid 'A' forms a white crystalline solid on treatment with NaHS03, it may be an aldehyde or a methyl ketone.                                                                            Further since liquid 'A' forms a bright silver mirror on treatment with a freshly prepared ammoiml solution of therefore, liquid 'A' is an aldehyde.                                    (ii) Since liquid 'B' forms a white crystalline solid on treatment with NaHS03, it may be an aldehyde or a methyl ketone.                                                                              Further since liquid 'B' does not give test with ammoniacal  solution, therefore, liquid 'B' must a methyl ketone.                                                                            Chemical equations for the reactions discussed are : No silver mirror