Which are Lewis acids and which are Lewis bases?

$$\begin{gathered} \left(a\right)\mathbf{}\mathit{C}{\mathit{u}}^{\mathbf{2}\mathbf{+}} \\ \left(b\right)\mathbf{}\mathit{C}{\mathit{l}}^{\mathbf{-}} \\ \left(c\right)\mathbf{}\mathit{S}\mathit{n}\mathit{C}{\mathit{l}}_{\mathbf{2}} \\ \left(d\right)\mathbf{}\mathit{O}{\mathit{F}}_{\mathbf{2}} \end{gathered}$$

A Lewis acid is a chemical species with an empty orbital that can accept an electron pair from a Lewis base and create a Lewis adduct.

(a)

$\mathit{C}{\mathit{u}}^{\mathbf{2}\mathbf{+}}$: Copper ion has a positive charge. It has an electron deficiency but can take electrons.

As a result, it's a Lewis acid.

(b)

$\mathit{C}{\mathit{l}}^{\mathbf{-}}$: The chloride ion has a negative charge. It has a high electron density and can donate electrons.

As a result, it's a Lewis base.

c)

$\mathit{S}\mathit{n}\mathit{C}{\mathit{l}}_{\mathbf{2}}$: Because the octet of tin in $\mathit{S}\mathit{n}\mathit{C}{\mathit{l}}_{\mathbf{2}}$is incomplete, it is electron-deficient. The two electronegative chlorine atoms connected to it also drive electron density away from the center atom, causing it to become more positive or electron-deficient.

As a result, $\mathit{S}\mathit{n}\mathit{C}{\mathit{l}}_{\mathbf{2}}$is classified as a Lewis acid.

(d)

$\mathit{O}{\mathit{F}}_{\mathbf{2}}$: The central atom in $\mathit{O}{\mathit{F}}_{\mathbf{2}}$is oxygen, which possesses two lone pairs. The oxygen in the middle has a lot of electrons.

As a result, it's a Lewis base.