The metal which displaces hydrogen from a boiling caustic soda solution is

$P_4 + 3 NaOH + 3 H_2 O \xrightarrow{CO_2} 3 X + PH_3 \uparrow$
$X \xrightarrow{HCl_{(aq)}} Y + NaCl$
The incorrect statement about $Y$ is

Determine whether the following statements are True $(T)$ or False $(F)$:
$1.$ Ammonia is produced from a mixture of $SO_2$ and $N_2$.
$2.$ $N_2H_2$ and $N_2H_4$ are formed from a mixture of $N_2/H_2$ in the Haber process.
$3.$ Compounds of $d$ or $f$ block elements are not used as catalysts in the Haber process.

Which of the following reactions is a part of the large-scale industrial preparation of nitric acid?

Nitrogen dioxide $(NO_2)$ reacts with water to give:

Which of the following substances is the most acidic?