An element has 6 electrons in its valence shell and the principal quantum number of last electron is 3. Its trioxide when combines with water gives acid (A). Answer the following questions :
`A+"'Oxygen'"rarrB`
What is the sum of oxidation state of central atom and number of `pi` bonds present in B?

Options

A. 7
B. 8
C. 6
D. 10

Answer

B

Explanation

`ArarrH_(2)SO_(4)XrarrH_(2)S_(2)O_(8) H-O-overset(O)overset(||)underset(O)underset(||)"S"-O-O-overset(O)overset(||)underset(O)underset(||)"S"-O-H`
`YrarrH_(2)SO_(3),ZrarrH_(2)S_(2)O_(5),BrarrH_(2)SO_(5)`
`H-O-overset(O)overset(||)underset(O)underset(||)"S"-O-O-Hunderset("Oxidation state"rarr+6)(pirarr2)`