Question

Assertion: In the reaction, $SnC{{l}_{4}}+2C{{l}^{-1}}\to {{\left[ SnC{{l}_{6}} \right]}^{2-}}$ , $SnC{{l}_{4}}$ is a Lewis acid.
Reason: Lewis acid accepts electrons.
A.Both assertion and reason are true and reason is the correct explanation of assertion.
B.Both assertion and reason are true but reason is not a correct explanation of assertion.
C.Assertion is true but reason is false.
D.Assertion is false but reason is true.
E.Both assertion and reason are false.

Answer 1

Lewis is defined as a substance which accepts non-bonding electrons, and it is also known as electron pair acceptor. Lewis acid is electrophilic in nature. When Lewis base reacts with Lewis acid it forms a Lewis adduct. Tin is an element having atomic number$50$ and its symbol is $Sn$ . Here, $SnC{{l}_{4}}$ is a Lewis acid.
Complete step by step answer:
Before talking about the answer we should know about Lewis acid base theory. In Lewis acid base theory there is a Lewis acid base reaction where Lewis base donates its electrons to Lewis acid to form a Lewis adduct. Here $SnC{{l}_{4}}$ is a Lewis acid and $C{{l}^{-1}}$ is a Lewis base.
Before talking about the answer, we should know about the electronic configuration of $Sn$. The electronic configuration of $Sn$is $\left[ Kr \right]4{{d}^{10}}5{{s}^{2}}5{{p}^{2}}$.
$Sn$ has vacant $d$ orbital which allows $Sn$ to accept electron pair from chlorine having negative charge. Here, chlorine can donate its electron to $Sn$ .
Now let us see the reaction,
$SnC{{l}_{4}}+2C{{l}^{-1}}\to {{\left[ SnC{{l}_{6}} \right]}^{2-}}$
Hence, $SnC{{l}_{4}}$ acts as a Lewis acid.
So, the correct option is (A) which is, both assertion and reason are true, and reason is the correct explanation of assertion.

Additional information
In Lewis model, the active species are ${{H}^{+}}$ ions which accept electron pairs from $O{{H}^{-}}$ and form a covalent bond. It complements the model of oxidation- reduction reaction. In these reactions, there is a transfer of electrons from one atom to another with the total change in oxidation number of one or more than one atom.
Let us see another reaction:
$SnC{{l}_{2}}+2C{{l}^{-}}\to {{\left[ SnC{{l}_{4}} \right]}^{2-}}$
where, $SnC{{l}_{2}}$ is a Lewis acid.

Note:
Lewis acids are considered as electrophilic in nature that means they are electron loving. When acid bonds with base, it uses the lowest unoccupied molecular orbital. It is the lowest energy that has the scope to accept electrons.
When Lewis acid reacts with Lewis base they form a coordinate covalent bond. Coordinate covalent bond is a dative bond in which the two electrons derive from the same atom. It is also known as two centre two electron covalent electron bonds.