Which of the following compounds contains both polar and non-polar bonds?

The atomic numbers of the elements $X, Y, Z$ are $a, a+1, a+2$ respectively. $Z$ is an alkali metal. The nature of bonding in the compound formed by $X$ and $Z$ is

Which of the following is not correct for ionic crystals?

Between $HF$,$HCl$,$HBr$ and $HI$,$HF$ has the highest ionic character because

Among the bonds formed by a chlorine atom with atoms of hydrogen,chlorine,sodium,and carbon,the strongest bond is formed between:

The Born-Haber cycle for $KCl$ is evaluated with the following data:
$\Delta_{f} H^{\ominus}$ for $KCl = -436.7 \ kJ \ mol^{-1}$
$\Delta_{sub} H^{\ominus}$ for $K = 89.2 \ kJ \ mol^{-1}$
$\Delta_{ionization} H^{\ominus}$ for $K = 419.0 \ kJ \ mol^{-1}$
$\Delta_{electron \ gain} H^{\ominus}$ for $Cl_{(g)} = -348.6 \ kJ \ mol^{-1}$
$\Delta_{bond} H^{\ominus}$ for $Cl_2 = 243.0 \ kJ \ mol^{-1}$
The magnitude of lattice enthalpy of $KCl$ in $kJ \ mol^{-1}$ is ..... . (Nearest integer)