Question

Dissolution of $S{O_3}$ in water is

Answer 1

$S{O_3}$ dissolves in water and gives a high amount of heat. It produces white fumes. Sulfur trioxide $S{O_3}$ reacts with water to produce ${H_2}S{O_4}$. It is highly corrosive. Directly $S{O_3}$ cannot be dissolved in water as the reaction is highly exothermic.

Complete answer:
Sulfur trioxide $S{O_3}$ is a white colorless crystalline solid. It is a precursor to sulfuric acid. It exists in many forms-solid polymer, crystalline trimmer, and gaseous monomer. It is a highly reactive compound and a very strong oxidizing agent. It is a thermodynamically unstable compound to selenium dioxide. It is the most important economical compound.$S{O_3}$ in gaseous form is a precursor to acid rain. It is solid below room temperature.
The structure of sulfur trioxide contains one sulfur atom bonded to three oxygen atoms. Sulfur is bonded to three oxygen atoms through the double bond. Every oxygen atom has two lone pairs; sulfur doesn’t have any lone pairs. Sulfur dioxide undergoes oxidation in the presence of air to produce $S{O_3}$
$S{O_3}$ is reactive in water. Sulfur trioxide $S{O_3}$ dissolves in water and reacts with it to form an aqueous solution of sulfuric acid (${H_2}S{O_4}$). The reaction is exothermic and explosive. $S{O_3}$ picks up the water easily when exposed to sunlight and then it gives white fumes. With the release of heat $S{O_3}$ reacts with water violently and forms pure sulfuric acid. Therefore the dissolution of $S{O_3}$ is an exothermic reaction.

Note:
When $S{O_3}$ reacts with water it gives aqueous${H_2}S{O_4}$. The vapor in equilibrium with the solution contains both $S{O_3}$ and ${H_2}O$. If enough$S{O_3}$is added, the entirety of the water will produce a pure form of ${H_2}S{O_4}$. And if more of $S{O_3}$ is added it will dissolve to form a solution of $S{O_3}$ and ${H_2}S{O_4}$. This solution is known as oleum or fuming sulfuric acid (${H_2}{S_2}{O_7}$)