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J. W. Hill, R. H. Petrucci, T. W. McCreary, & S. S. Perry General Chemistry 4th edition

Problem 15.101

Identify the Lewis acid and Lewis base in each of the following reactions.

(a) OH(aq) + Al(OH)3(s) Al(OH)4(aq)

(b) Cu2+(aq) + 4 NH3(aq) [Cu(NH3)4]2+(aq)

(c) CO2(g) + OH(aq) HCO3(aq)




Answer:

Lewis acids are electron pair acceptors (often cationic) and Lewis bases are electron pair donors (often anionic or have a free lone pair of electrons to donate).
(a)
OH(aq)
+
Al(OH)3(s)
Al(OH)4(aq)
Lewis

Base

(anion)

Lewis

Acid

(incomplete octet)





(b)
Cu2+(aq)
+
4 NH3(aq)
[Cu(NH3)4]2+(aq)
Lewis

Acid

(cation)

Lewis

Base

(lone pair on N)





(a)
CO2(g)
+
OH(aq)
HCO3(aq)
Lewis

Acid

Lewis

Base

(anion)