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SOME IMPORTANT COMPOUNDS OF BORON


                    I.BORAX (Na 2B 4O 7⋅10H 2O) :It is white crystalline solid .

                       •  Na2B4O7 + 7H2O → 2NaOH + 4H3BO3

                                                  Δ                Δ
                       •  Na  2B  4O  7⋅10H  2O   → Na  2B  4O  7  →   aBO 2 + B 2O 3

                    II.ORTHOBORIC ACID(H3BO3)

                              •  Na2B4O7 + 2HCl + 5H2O → 2NaCl + 4B(OH)3

                                                   Δ         Δ
                              •  B2O3.H3BO3  → HBO2→B2O3
                                 III.DIBORANE (B2H6)


                    PREPARATION: 4BF3 + 3 LiAlH4 → 2B2H6 + 3LiF + 3AlF3

                                 2NaBH4 + I2 → B2H6 + 2NaI + H2
                                                 450K
                                 2BF 3 + 6NaH ⎯  B2 H 6 + 6Na


                    PROPERTIES: B2H6(g) + 6H2O(l) → 2B(OH)3(aq) + 6H2(g)

                           B2H6 + 2 NMe3 → 2BH3⋅NMe3   ,        B2H6 + 2 CO → 2BH3⋅CO


                    •  Reaction of NH3   with diborane gives initially B2H6.2NH3 which is

                       formulated as [BH2(NH3)2] [BH4] ; further heating gives

                       borazine, B3N3H6 known as “inorganicbenzene”

                    USES OF BORON AND ALUMINIUM AND THEIR COMPOUNDS

                          i.Metal borides are used in nuclear industry .Borax and boric

                          acid is in the manufacture of heat resistant glasses (e.g., Pyrex),
                          glass-wool and fibreglass.ii. Borax is also used as a flux for

                          soldering metals, constituent of medicinal soaps. An aqueous
                          solution of orthoboric acid is generally used as a mild

                          antiseptic.Aluminium and its alloys can be given shapes of pipe,
                          tubes,rods, utensil making,construction, aeroplane and

                          transportation industry.
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