Polarity in a molecule and hence the dipole moment depends primarily on the electronegativity of the constituent atoms and shape of a molecule. Which of the following has the highest dipole moment?

Isostructural species are those which have the same shape and hybridisation. Among the given species identify the isostructural pairs.

The types of hybrid orbitals of nitrogen in NO₂⁺ , NO₃^- and NH₄⁺ respectively are expected to be

Hydrogen bonds are formed in many compounds e.g., H₂O, HF, NH₃ . The boiling point of such compounds depends to a large extent on the strength of hydrogen bond and the number of hydrogen bonds. The correct decreasing order of the boiling points of above compounds is :

In PO₄^3- ion the formal charge on the oxygen atom of P–O bond is