Answer: It is a Lewis acid/base reaction, and [tex]Fe^{3+}[/tex] is the Lewis acid.
Explanation:
According to the Lewis concept, an acid is defined as a substance that accepts electron pairs and base is defined as a substance which donates electron pairs.
[tex]Fe^{3+}[/tex] can readily accept electrons and thus act as a lewis acid which is short of electrons.
[tex]CN^-[/tex] can readily lose electrons and thus act as a lewis base which has excess of electrons.
It is a Lewis acid/base reaction, and [tex]Fe^{3+}[/tex] is the Lewis acid.
