What characteristics do you expect from an electron-deficient hydride with respect to its structure and chemical reactions?

Explanation

(i) Electron-deficient hydrides do not have sufficient number of electrons to form normal covalent bonds. Therefore, in order to make up the electron deficiency, they exist in polymeric forms such as `B_(2)H_(5), B_(4)H_( 10), (AIH_(3))_(n)`, etc. (ii) Due to deficiency of electrons, electron-deficient hydrides act as Lewis acids and form complexes with Lewis bases.
For example,

(iii) Due to deficiency of electrons, electron-deficient hydrides . are very reactive and react with several metals, non-metals and compounds. For example,
`B_(2)H_(6)+6Cl_(2)to2BCl_(3)+6HCl`
`B_(2)H_(6)+3O_(2)toB_(2)O_(3)+3H_(2)O`
`B_(2)H_(6)+HCloverset(AlCl_(3))toB_(2)H_(5)Cl+H_(2)`
`B_(2)H_(6)+2KOH+2H_(2)Oto2KBO_(3)+6H_(2)`