When oxygen is passed through a solution of $Na_2SO_3$,we get:

Oxygen is more electronegative than sulphur,yet $H_2S$ is acidic while $H_2O$ is neutral. This is because

Below are two statements. One is labeled as Assertion $(A)$ and the other as Reason $(R):$
Assertion $(A):$ $H_2Te$ is more acidic than $H_2S$.
Reason $(R):$ The bond dissociation enthalpy of $H_2Te$ is less than that of $H_2S$.
In the context of the above statements,choose the correct answer from the following options:

Which of the following activities results in the formation of oleum in the manufacture of sulphuric acid by the contact process?

The formula of ozone is $O_3$,it is

Write the molecular formula of Marshall's acid.