The Foundations of Chemistry

Cl

Cl

Cl

Cl

Sn

SnCl 4 (
) 2Cl(aq) SnCl 62 (aq)

2 

2Cl

acid base

Cl

Cl

Cl Cl

Cl Cl

Sn

Sn is sp^3 d^2 hybridized

(octahedral)

Sn is sp^3 hybridized

(tetrahedral)

390 CHAPTER 10: Reactions in Aqueous Solutions I: Acids, Bases, and Salts

Problem-Solving Tip:Which Acid–Base Theory Should You Use?

Remember the following:

1.Arrhenius acids and bases are also Brønsted–Lowry acids and bases; the reverse is not

true.

2.Brønsted–Lowry acids and bases are also Lewis acids and bases; the reverse is not

true.

3.We usually prefer the Arrhenius or the Brønsted–Lowry theory when water or another

protonic solvent is present.

4.Although the Lewis theory can be used to explain the acidic or basic property of some

species in protonic solvents, the most important use of the Lewis theory is for acid-

base reactions in many nonaqueous solvents.

Many organic and biological reactions are acid–base reactions that do not fit within

the Arrhenius or Brønsted–Lowry theories. Experienced chemists find the Lewis theory

to be very useful because so many other chemical reactions are covered by it. The less

experienced sometimes find the theory less useful, but as their knowledge expands so does

its utility.

2–

• 2Cl–