If the value of ionic radius ratio $\left( \frac{r_c}{r_a} \right)$ is $0.52$ in an ionic compound,the geometrical arrangement of ions in the crystal is:

In the series $HCl$,$HBr$ and $HI$,the boiling point increases in the order $HCl < HBr < HI$. This is due to

Which of the following orders of molecular force of attraction among the given species is incorrect?

In which molecule is the van der Waals force likely to be the most important factor in determining the melting point $(m.pt.)$ and boiling point $(b.pt.)$?

$A$ solid melts at a temperature above $100\,^oC$ and is a non-conductor of electricity in both solid and molten states. It is soluble in hydrocarbon solvents. What is the most likely structure of the solid?

What is the dependence of interaction energy on the distance $(r)$ between molecules for the following forces?
$(i)$ London forces
$(ii)$ Dipole-dipole forces (stationary)
$(iii)$ Dipole-induced dipole forces