When a colored gas is passed through bromine water,the color is discharged. Which gas is it?

An oxide of an element is a gas and dissolves in water to give an acidic solution. The element belongs to:

In the following reaction,identify the nature of the product formed by the complete hydrolysis of the underlined atom at $R.T.$:
$\underline{S}OCl_2 + H_2O \longrightarrow H_2SO_3 + HCl$

Which of the following statements are correct?
$(a)$ The isotope of carbon containing $7$ neutrons has natural abundance of $1.1 \%$.
$(b)$ Among the $IV$ $A$ group elements,$Sn$ has the lowest melting point.
$(c)$ Silicon is the $2^{nd}$ (by mass) most abundant element in the earth's crust.
$(d)$ Elemental carbon shows the highest electrical resistivity among the $14$ group elements.

Which of the following oxides is amphoteric?

Concentrated hydrochloric acid,when exposed to air,sometimes produces a white cloud of smoke. What is the explanation for this?