The single largest industrial application of dihydrogen is :

Given below are two statements : One is labelled as Assertion A and other is labelled as Reason R.

Assertion A : The dihedral angles in H₂O₂ in gaseous phase is 90.2$$^\circ$$ and in solid phase is 111.5$$^\circ$$.

Reason R : The change in dihedral angle in solid and gaseous phase is due to the difference in the intermolecular forces.

Choose the most appropriate answer from the options given below for A and R.

In basic medium, H₂O₂ exhibits which of the following reactions?

(A) Mn²⁺ $$ \to $$ Mn⁴⁺

(B) I² $$ \to $$ I^$$-$$

(C) PbS $$ \to $$ PbSO₄

Choose the most appropriate answer from the options given below :

The functional groups that are responsible for the ion-exchange property of cation and anion exchange resins, respectively, are :