CHAPTER 06: CHEMICAL

EQUILIBRIUM

Harris: Quantitative Chemical Analysis, Eight Edition

CaCO3(s) ＋ CO2(aq) ＋ H2O(l) = Ca2 ＋ (aq) ＋ 2HCO3 － (aq)

HCO3 － (aq) ＋ H ＋ (aq) s --- > CO2(g) ＋ H2O(l)

aA + bB = cC + dD in its standard state

HA = H ＋ ＋ A － K1 ＝ [H ＋ ][A － ] / [HA] 만약 반응의 방향을 바꾸면 새 K 값은 처음 K 값의 역수가 된다 .H ＋ ＋ A － = HA K1′ ＝ [HA] / [H ＋ ][A－ ] ＝ 1/K1 HA = H ＋ ＋ A － K1

H ＋ ＋ C = CH ＋ K2

----------------------------------HA ＋ C = A － ＋ CH ＋ K3

K3 ＝ K1K2 ＝ [H ＋ ][A － ] / [HA] ·[CH ＋ ] / [H ＋ ][C] ＝ [A － ] ·[CH ＋ ] / [HA] [C]

Le Chˆatelier’s principle:

Reaction quotient:

Because Q > K, the reaction must go to the left

When the temperature changes:

The term including e ᅀ S/R is independent of T. The term e- ᅀ H/RT increases with increasing temperature if ᅀ Ho is positive, and decreases if it is negative.

K of the endothermic reaction increases if T is raised.K of the exothermic reaction decreases if T is raised.

6-3 Solubility product

Ion pair

Disproportionation: an element in an intermediate oxidation state gives products.

Common ion effect

A salt will be less soluble if one of its constituent ions is already present in the solution.

Separation by Precipitation

Co-precipitation: foreign ions adsorbed on the precipitate.

Q < Ksp for PbI2, Pb ions will not precipitate.

Lewis Acid and Bases

6-4 Complex Formation

Effect of Complex Ion Formation on Solubility

6-5 Protic Acids and Bases

- Hydronium ion: H3O+

Brønsted－ Lowry Acids and Bases: Acid: proton donor, Base: proton acceptor

Salt: Any ionic solid

When [I-] = 1.0 M, [Pb]total = 3.2 x 10-4 M

Conjugate Acids and Bases

- Structure of Hydronium ion

The Nature of H+ and OH-

Autoprotolysis

- Protic solvents have a reactive H+

6-6 pH

Is There Such a Thing as Pure Water?

6-7 Strength of Acids and Bases

Strong Acids and Bases

Weak Acids and Bases

Ka: Acid dissociation constant

Kb: Base hydrolysis constant

Common Classes of Weak Acids and Bases

Polyprotic Acids and Bases

Kal ( 또는 K1) 은 가장 많은 양성자를 가진 산성 화학종에 대한 것이고 , Kbl 은 가장 적은 양성자를 가진 염기성 화학종에 대한 것이다 .

Relationship between Ka and Kb

Carbonic Acid

6-8 Solving Equilibrium Problems