Question

Which statements are true out of the following :
$S_1$ : $AgI$ is less soluble in water than $AgF$ due to more polarization of $I^{-}$ in comparison to $F^{-}$ ion.
$S_2$ : The melting point of $BaC{l}_2$ is higher than the melting point of $BeC{l}_2$ due to greater ionic nature of $BaC{l}_2$.
$S_3$ : The order of hydrated radii is : $A{l}^{3+}\left(aq\right)>M{g}^{2+}\left(aq\right)>N{a}^{+}\left(aq\right)$

$S_4$: Thermal stability of alkali metal carbonates decreases down the group,

• A. $S_1$
• B. $S_2$
• C. $S_3$
• D. $S_4$

Answer 1

Answer: (A), (B), (C)

The correct options are
A $S_1$
B $S_2$
C $S_3$

$S_1$ : According to Fajan's rule, polarizability of $I^{-}$ in $AgI$ is higher than that of $F^{-}$ in $AgF$. Hence $AgI$ is less soluble than $AgF$, due to its high covalent nature.

$S_2$ : $B{a}^{2+}$ ion has low charge density due to its larger size when compared to $B{e}^{2+}$ ion. Hence it has a low polarizing power when compared to $B{e}^{2+}$. So, according to Fajan's rule, $BaC{l}_2$ has a higher ionic character and thus has a higher melting point.

$S_3$ : Higher the charge density, larger will be the hydrated radii.
Order of charge density : $A{l}^{3+}>M{g}^{2+}>N{a}^{+}$
Hence, the order of hydrated radii will follow the same order i.e. $A{l}^{3+}\left(aq\right)>M{g}^{2+}\left(aq\right)>N{a}^{+}\left(aq\right)$

$S_4$: Stability of the alkali metal carbonates depends on the polarising power of the cation. Smaller the size of the cation, greater the polarising power and smaller the stability. Hence stability of the carbonates increases down the group.