Diborane is formed the element as shown in equation (1)
`2B(s) + 3H_(2)(g) rarr 3B_(2)H_(6)(g)"…….."(1)`
Given that
`{:(H_(2)O(l)rarrH_(2)O(g),DeltaH_(1^(@))=44kJ),(2B(s)+3//2O_(2)(s)rarrB_(2)O_(3)(s),DeltaH_(2^(@))=-1273kJ),(B_(2)H_(6)(g)+3O_(2)(g)rarrB_(2)O_(3)(s)+3H_(2)O(g),DeltaH_(3^(@))=-2035 kJ),(H_(2)(g)+1//2O_(2)(g)rarrH_(2)O(l),DeltaH_(4^(@))=-286kJ):}`
the `DeltaH^(@)` for the reaction (1)` is -