The correct statements among $I$ to $III$ regarding group $13$ element oxides are,
$I$. Boron trioxide is acidic
$II$. Oxides of aluminium and gallium are amphoteric
$III$. Oxides of indium and thallium are basic

For the following halides: $(1) \ BCl_3$,$(2) \ AlCl_3$,$(3) \ GaCl_3$,$(4) \ InCl_3$,what is the decreasing order of their Lewis acid strength?

The Lewis acid strength of $BBr_3$,$BCl_3$,and $BF_3$ is in the order:

$A$ certain salt $X$ gives the following results:
$(i)$ Its aqueous solution is alkaline to litmus.
$(ii)$ It swells up to a glassy material $Y$ on strong heating.
$(iii)$ When conc. $H_{2}SO_{4}$ is added to a hot solution of $X,$ white crystals of an acid $Z$ separate out.
Write equations for all the above reactions and identify $X, Y,$ and $Z$.

The incorrect statement from the following for borazine is:

Which of the following complex ions does not exist?