Borax is actually made of two tetrahedra and two triangular units joined together and should be written as : $Na_2[B_4O_5(OH)_4]·8H_2O$

Consider the following statements about borax :

$a.$  Each boron atom has four $B-O$ bonds

$b.$  Each boron atom has three $B-O$ bonds

$c.$  Two boron atoms have four $B-O$ bonds while other two have three $B-O$ bonds

$d.$  Each boron atom has one $-OH$ groups

Select correct statement(s) :

The incorrect statement regarding above reactions is

$\mathop {Al}\limits_{metal} \xrightarrow[{(aq.)}]{{HCl}}'X' + Gas\,'P'$

$\mathop {Al}\limits_{metal} \xrightarrow[{ + {H_2}O}]{{NaOH\,(aq.)}}'Y' + Gas\,'Q'$

Give suitable laboratory preparation for diborane.

Aluminium chloride exists as dimer, $A{l_2}C{l_6}$ in solid state as well as in solution of non-polar solvents such as benzene. When dissolved in water, it gives

A layer of coke is spread over bauxite during electrolytic reduction of alumina by Hall-Heroult process. This layer acts as a/an:

The purification of alumina is called