Addition of mineral acid to an aqueous solution of Borax,the following compound is formed:

In diborane $(B_2H_6)$,the $H-B-H$ bond angles are approximately ...

Which of the following statements is incorrect?

Write balanced equations for :
$(i) \, BF_{3} + LiH \to $
$(ii) \, B_{2}H_{6} + H_{2}O \to $
$(iii) \, NaH + B_{2}H_{6} \to $
$(iv) \, H_{3}BO_{3} \xrightarrow{\Delta }$
$(v) \, Al + NaOH \to $
$(vi) \, B_{2}H_{6} + NH_{3} \to $

The number of three-centre two-electron $(3c-2e)$ bonds in a molecule of diborane $(B_2H_6)$ is

The correct formula of borax is