Explain with reason: `SnCl_2` is a solid ionic compound whereas `SnCl_4` is a covalent liquid.

Explanation

`SnCl_2mSn(II): [Xe]4 d^10 5s^2`
`SnCl_4, Sn(IV): [Xe] 4d^10`
Here with increase in oxidation state from Sn(II) to Sn(IV) the ionisation potential of the central atom (here Sn) increases which makes the Sn-Cl bonds more covalent in `SnCl_4` compared to `SnCl_2`- Fajan's rules. Hence the `SnCl_2` molecules are closely packed due to greater ionic character whereas in `SnCl_4` the molecules show weaker London forces of interaction due to covalent nature. This explains the given observation.