Identify the compounds $A$,$X$ and $Z$ in the following reactions :
$A + 2HCl + 5H_2O \to 2NaCl + X$
$X$ $\xrightarrow[370 \ K]{\Delta} HBO_2$ $\xrightarrow[> 370 \ K]{\Delta} Z$

The correct statements about the compounds of boron are:
$I$. In borax bead test, the colour of cobalt metaborate is blue.
$II$. Diborane is prepared by the oxidation of sodium borohydride with iodine.
$III$. In diborane, the oxidation state of hydrogen is $+1$.
$IV$. Boric acid is a tribasic acid.

Two elements $X$ and $Y$ combine separately with a highly electropositive metal to form binary compounds,which upon hydrolysis yield borane and silane,respectively. What are $X$ and $Y$?

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$ : Boric acid is a weak acid.
Reason $R$ : Boric acid is not able to release $H^{+}$ ion on its own. It receives $OH^{-}$ ion from water and releases $H^{+}$ ion.
In the light of the above statements,choose the most appropriate answer from the options given below.

Write the chemical reaction of $Al$ with aqueous alkali.

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