The correct statement$(s)$ for orthoboric acid is/are

$(A)$ It behaves as a weak acid in water due to self ionization.

$(B)$ Acidity of its aqueous solution increases upon addition of ethylene glycol.

$(C)$ It has a three dimensional structure due to hydrogen bonding.

$(D)$ It is weak electrolyte in water.

When borax is heated with $CoO$ on a platinum loop, blue coloured bead formed is largely due to

Give reasons:

$(i)$ Conc. $HNO _{3}$ can be transported in aluminium container.

$(ii)$ $A$ mixture of dilute $NaOH$ and aluminium pieces is used to open drain.

$(iii)$ Graphite is used as lubricant.

$(iv)$ Diamond is used as an abrasive.

$(v)$ Aluminium alloys are used to make aircraft body.

$(vi)$ Aluminium utensils should not be kept in water overnight.

$(vii)$ Aluminium wire is used to make transmission cables.

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

Inorganic graphite is:

Which of the following statement is not correct about diborane?