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

$A$. What are silicones? State the uses of silicones.
$B$. What are boranes? Give chemical equation for the preparation of diborane.

Boron cannot form which one of the following anions?

Consider the following flow diagram for the extraction of borax from colemanite:
$2CaO \cdot 3B_2O_3 + Na_2CO_3 \xrightarrow{\text{aq. medium}} Z \text{ (Residue/ppt)} + \text{Filtrate}$
$\text{Filtrate} \xrightarrow{\text{Crystallisation & Filtration}} X \text{ (in filtrate)} + Y \text{ (Residue)}$
$X + CO_2 \to Y$
Identify compounds $X$ and $Y$ respectively.

Which of the following oxides is acidic in nature?

Which of the following statements is/are correct for group $13$ elements?
$A$. $Al$ reacts with dil. $HCl$ to liberate $H_2$ gas
$B$. $Al$ reacts with conc. $HNO_3$ to liberate $H_2$ gas
$C$. Boron reacts with only acids to liberate $H_2$ gas
$D$. Anhydrous $AlCl_3$ reacts with moisture to liberate $H_2$ gas