Boron, the first member of group 13 (p-block) is a typical non-metal. H exists in two allotropic forms. The compounds of boron are mainly electron deficient as well as Lewis acids. For example, all the trihalides of boron `(BX_(3))` are Lewis acids. The expected order of acidic strength based on the electro negativity of halogen atoms is : `BF_(3)gtBC l_(3)gtBBr_(3)gtBl_(3)`. But the actual order is the reverse. This is explained with the help of the concept of back bonding `(p pi- p pi)` . Among the hydrides of boron. diborane has a bridged structure. In the reaction: `BF_(3)+3LiBH_(4)rarr3liF+X` isA. `B_(4)H_(10)`B. `AlCl_(3)`C. `B_(2)H_(6)`D. `B_(3)H_(8)`

Boron, the first member of group 13 (p-block) is a typical non-metal.

1.	Boron, the first member of group 13 (p-block) is a typical non-metal. H exists in two allotropic forms. The compounds of boron are mainly electron deficient as well as Lewis acids. For example, all the trihalides of boron `(BX_(3))` are Lewis acids. The expected order of acidic strength based on the electro negativity of halogen atoms is : `BF_(3)gtBC l_(3)gtBBr_(3)gtBl_(3)`. But the actual order is the reverse. This is explained with the help of the concept of back bonding `(p pi- p pi)` . Among the hydrides of boron. diborane has a bridged structure. In the reaction: `BF_(3)+3LiBH_(4)rarr3liF+X` isA. `B_(4)H_(10)`B. `AlCl_(3)`C. `B_(2)H_(6)`D. `B_(3)H_(8)`
Answer» X is `B _(2 )H_(6)` (diborane).

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