What are $X$ and $Y$ respectively in the following reactions?
$X \xleftarrow{CO} B_2 H_6 \xrightarrow[(C_2 H_5)_2 O]{NaH} Y$

Consider the compounds,$BCl_3$ and $CCl_4$. How will they behave with water? Justify.

Which of the following produce an alkaline solution when dissolved in water?
$(i)$ Borax
$(ii)$ Potash alum
$(iii)$ $SO_2$
$(iv)$ $SO_2(OH)_2$

What is the product formed by the action of caustic soda on aluminum hydroxide?

$BCl_3 + H_2O \longrightarrow$ Product,here product is:

$A$ nonmetallic element of group $13$,used in making bulletproof vests,is an extremely hard solid of black colour. It can exist in many allotropic forms and has an unusually high melting point. Its trifluoride acts as a Lewis acid towards ammonia. The element exhibits a maximum covalence of four. Identify the element and write the reaction of its trifluoride with ammonia. Explain why the trifluoride acts as a Lewis acid.