Question

An example of a Lewis acid is

A) $NaCl$

B) $MgC{l}_2$

C) $AlC{l}_3$

D) $SnC{l}_4$

Answer 1

Hint: From the definition of the Lewis acids, the Lewis acids are the acids which can accept the paired electrons or they are having some vacant orbitals to fill the electrons. $B{F}_3$ and $Al{F}_3$ are some examples of Lewis acids.

Complete Step By Step Answer:

First of all we will discuss the definition of the Lewis acids:

Lewis acid: The Lewis acids are the acids which can accept the paired electrons or they are having some vacant orbitals to fill the electrons. $B{F}_3$ and $Al{F}_3$ are some examples of Lewis acids.

So, from analysing the definition of the Lewis acid, we will see all the options.

In the first option, $NaCl$ has no vacant orbitals. So, $NaCl$ is not a Lewis acid.

In the second option, $MgC{l}_2$ has no vacant orbitals. So, $MgC{l}_2$ is not a Lewis acid.

In the third option, $AlC{l}_3$ has vacant orbitals. So, $AlC{l}_3$ is a Lewis acid.

In the last option, $SnC{l}_4$ has no vacant orbitals. So, $SnC{l}_4$ is not a Lewis acid.

Hence, $AlC{l}_3$ is an example of Lewis acid.

Hence, the correct option is (c) $AlC{l}_3$.

Additional Information:

There are various definitions of the acids. Few are as follows:

Arrhenius acids: According to Arrhenius, the Arrhenius acids are the acids which give ions when the acids are dissolved in the water.

Bronsted Lowry acids: According to Bronsted, the Bronsted Lowry acids are the acids which are proton donors, i.e, acids which have the tendency to donate protons.

Note :

There are various methods to measure the nature of the substances, whether they are acid, strong acid, neutral or base. Natural indicators like litmus, Methyl orange, litmus paper, pH paper etc.