The number of $2$-centre-$2$-electron and $3$-centre-$2$-electron bonds in $B_2H_6$,respectively,are

Identify the correct statements from the following:
$i$. $H_3BO_3$ is a monobasic acid.
$ii$. The correct formula of borax is $Na_2[B_4O_5(OH)_4] \cdot 8H_2O$.
$iii$. $NaBH_4$ is a reducing agent.

Which of the following statements is incorrect?

Choose the incorrect statement/reaction.

Conc. $HNO_3$ can be stored in a container of

Boron halides are Lewis acids because.....