Why is a Tyndall box used in the manufacture of sulfuric acid by the contact process?

The number of $S=O$ bonds present in sulphurous acid,peroxodisulphuric acid and pyrosulphuric acid,respectively are :

Which of the following dinegative anions is quite common?

Given below are two statements:
Statement-$I$: $\alpha$ and $\beta$ forms of sulphur can change reversibly between themselves with slow heating or slow cooling.
Statement-$II$: At room temperature the stable crystalline form of sulphur is monoclinic sulphur.
In the light of the above statements,choose the correct answer from the options given below:

Which of the following bonds has the highest bond dissociation energy?

Permono sulphuric acid is known as