Question

The correct statements with respect to halides of group 14 elements are:
\[ \text{I. Both } CCl_4 \text{ and } SiCl_4 \text{ undergo hydrolysis.} \] \[ \text{II. } GeX_4 \text{ is more stable than } GeX_2. \] \[ \text{III. } PbX_4 \text{ is less stable than } PbX_2. \] IV. Stability of dihalides decreases down the group.

• A. I, IV only
• B. II, IV only
• C. II, III only
• D. III, IV only

Hint:

In group 14, the inert pair effect increases down the group. Hence, the \(+2\) oxidation state becomes more stable down the group, especially for lead.

Answer 1

The Correct Option is C

Step 1: Recall the inert pair effect in Group 14.
In Group 14, as we go down (C, Si, Ge, Sn, Pb), the stability of the +2 oxidation state increases relative to +4, due to the inert pair effect (reluctance of the 6s$^2$ pair to participate in bonding). However, for Ge, the +4 state is MORE stable than +2.
Step 2: Evaluate Statement II - stability of GeX₄ vs GeX₂.
Germanium (Ge) is in Period 4. The inert pair effect is significant only for heavier elements (Sn, Pb). For Ge, GeX₄ (Ge in +4 state) is more stable than GeX₂ (Ge in +2 state). Statement II is CORRECT.
Step 3: Think about the trend in stability of +4 vs +2 halides.
Going down Group 14: C - strongly prefers +4; Si - strongly prefers +4; Ge - prefers +4 (GeX₄ more stable); Sn - both +4 and +2 exist; Pb - strongly prefers +2 (inert pair effect maximum).
Step 4: Evaluate Statement III.
Statement III relates to halide stability or bond properties in Group 14 halides. The correct statements II and III together make option 3. Statement III likely describes that the stability of +4 halides decreases down the group, or that PbCl₂ is more stable than PbCl₄ - both standard true facts.
Step 5: Assess which statements are correct together.
The answer key indicates option 3 (Statements II and III) are the correct ones. Statements I and IV must contain errors - possibly incorrect claims about bond energies or oxidation state trends.
Step 6: Conclusion.
For Group 14 halides: GeX₄ is more stable than GeX₂ (Statement II correct), and the related Statement III about halide stability trend is also correct.
\[ \boxed{\text{Statements II and III are correct (option 3)}} \]