Question

The stability of dihalides of Si,Ge.Sn, and Pb increases steadily in the sequence :

• A. $Ge{X}_2<Si{X}_2<Sn{X}_2<Pb{X}_2$
• B. $Si{X}_2<Ge{X}_2<<Pb{X}_2<Sn{X}_2$
• C. $Si{X}_2<Ge{X}_2<Sn{X}_2<Pb{X}_2$
• D. $Pb{X}_2<Ge{X}_2<Sn{X}_2<Si{X}_2$

Answer 1

The correct option is C $Si{X}_2<Ge{X}_2<Sn{X}_2<Pb{X}_2$

Due to the inert pair effect, the stability of $M^{2+}$ ions (of group IV elements) increases as we go down the group. The stability of dihalides increases down the group: $Si{X}_2<Ge{X}_2<Sn{X}_2<Pb{X}_2$
Hence, correct option is c.

THEORY
Stability of halides:
$Ge{X}_4$ is more stable than $Ge{X}_2$, but $Pb{X}_2$ is more stable than $Pb{X}_4$.
Heavier members Ge to Pb are able to make halides of formula $M{X}_2$. The stability of dihalides increases down the group.
Except for $CC{l}_4$ tetra-chlorides are easily hydrolysed by water. The central atom can accommodate the lone pair of electrons from the oxygen atom of water molecules in d orbital.
Hydrolysis of $SiC{l}_4$: