Identify the Lewis acid and Lewis base in each reaction:
(a)
(b)
(c)

The answers to the question are

(a)

(b)

(c)

Explanation:

Lewis theory of acids states that

An acid is a substance that accepts a pair of electrons an i doing so forms a covalent bond with the group that supplies the electrons

A Lewis base is a substance that donates an unshared pair of electrons to a recipient species with which the  electrons can be shared

(a) Here Fe₃⁺ is the Lewis acid as it accepts an electron pair from H₂O which is amphoteric an so can act either as a Lewis base or acid

Fe₃⁺ = Lewis acid

H₂O = Lewis base

(b) H₂O + H⁻ → H₂ + OH⁻

Here the water accepts a pair of electrons from H⁻ anion hence it is the Lewis acid while H⁻ anion donates a pair of electrons acting as the Lewis base

H₂O = Lewis acid

H⁻ = Lewis base

(c) 4CO⁺ +Ni ↔ Ni(CO₄) Here we have

CO⁺ = Lewis acid

Ni = Lewis base