question_answer

  (a) Draw the structures of the following molecules. (i)                                                         (ii) (b) Complete the following chemical equations. (i)                                     (ii)                    (iii)           [2+3] Or (a) What happens when (i) chlorine gas is passed through a hot concentrated solution of NaOH? (ii) sulphur dioxide gas is passed through an aqueous solution of a Fe (III) salt? (b) Answer the following. (i) What is the basicity ofH3P03 and why? (ii) Why does fluorine not play the role of a central atom in interhalogen compounds? (iii) Why do noble gases have very low boiling points?                                                                                       [2 +3]

Answer:

  (a) (i) (ii) is interhalogen compound Br and F both complete their octets. (b)  [1] (ii)                      [1] (iii)                                                        [1] Or (a)    (i)                                                         [1] (ii) FE (III) is reduced to Fe (II) (b) (i) has two ion sable H and is thus it is a dibasic acid. (ii) Because F is the most electronegative element of the halogen family as well as in the whole Periodic Table. It only formsand not. Thus it is never as the central atom in interhalogen compounds. Also it lacks d-orbital in which electrons can be expanded to give valency more than 1. Cl, Br, I with d-orbital can expand its valency to +1,+3,+5,+7                                                                           [1] (iii) They have only weak dispersion forces being monoatomic in nature. Thus, they have low boiling points.                                           [1]