Analyzing Statements About $SnCl_4$ and $SnMe_4$

The question asks us to identify the correct statements regarding the chemical properties of tin tetrachloride ($SnCl_4$) and tetramethyltin ($SnMe_4$). Let's examine each statement individually.

Statement A: $SnCl_4$ forms $SnCl_6^{2-}$

Explanation: $SnCl_4$ contains tin in the +4 oxidation state. Tin(IV) compounds can often expand their coordination number beyond 4. In the presence of excess chloride ions ($Cl^-$), $SnCl_4$ acts as a Lewis acid and can accept two additional chloride ligands to form the hexachlorostannate(IV) complex ion, $[SnCl_6]^{2-}$. This process is a common reaction illustrating the Lewis acidic nature and coordination flexibility of $Sn(IV)$. The Lewis acid-base reaction can be represented as:

$SnCl_4 + 2Cl^- \rightarrow [SnCl_6]^{2-}$

Conclusion: Statement A is correct.

Statement B: $SnMe_4$ does not form $SnMe_6^{2-}$

Explanation: $SnMe_4$ is tetramethyltin, where tin is also in the +4 oxidation state, bonded to four methyl ($Me$) groups. To form a species like $[SnMe_6]^{2-}$, tin would need to increase its coordination number to 6 by coordinating two additional methyl groups or other ligands. However, the methyl groups are significantly larger (more sterically bulky) than chloride ions. This steric hindrance makes it very difficult for two more methyl groups to coordinate effectively around the central tin atom. Consequently, $SnMe_4$ does not readily form such a hexacoordinate species.

Conclusion: Statement B is correct.

Statement C: $SnCl_4$ does not undergo hydrolysis

Explanation: $SnCl_4$ is a relatively volatile liquid that reacts readily with water. It is susceptible to hydrolysis because the tin(IV) center is a strong Lewis acid, and the Sn-Cl bonds are polar and can be attacked by the nucleophilic oxygen atom of water molecules. Hydrolysis leads to the formation of tin oxides or hydroxides and hydrochloric acid ($HCl$). A simplified reaction is:

$SnCl_4 + 2H_2O \rightarrow SnO_2 \downarrow + 4HCl$

Conclusion: Statement C is incorrect.

Statement D: $SnMe_4$ readily hydrolyses

Explanation: $SnMe_4$ is an organometallic compound. While organometallic compounds vary in their reactivity with water, tetramethyltin is considerably more stable towards hydrolysis compared to $SnCl_4$ under ambient conditions. The Sn-C bonds are strong covalent bonds, and the methyl groups provide some steric shielding. Significant hydrolysis typically requires more specific conditions, such as the presence of strong acids or bases, or heating. It does not "readily" hydrolyse in the same way that many inorganic halides do.

Conclusion: Statement D is incorrect.

Final Conclusion

Based on the analysis of each statement:

• Statement A is correct.
• Statement B is correct.
• Statement C is incorrect.
• Statement D is incorrect.

Therefore, the correct statements are A and B only.