Polyprotic Acids and Salt Solutions in Chemistry

Polyprotic acids

Acids with multiple protons to donate.

H2SO3

Sulfurous acid, a polyprotic acid example.

Ka1

First acid-dissociation constant, 1.7 x 10^-2.

Ka2

Second acid-dissociation constant, 6.4 x 10^-8.

Acid dissociation

Process of losing H+ ions from acids.

pH dependence

Depends on first dissociation if Ka1 > 1000 x Ka2.

Ascorbic acid

Vitamin C, a polyprotic acid.

Citric acid

Common polyprotic acid in citrus fruits.

Salt solutions

Solutions formed by dissolving salts in water.

Neutral salts

Salts like NaCl that do not affect pH.

Hydrolysis

Reaction of ions with water producing H+ or OH-.

Conjugate base

Anion formed when an acid donates H+.

Conjugate acid

Cation formed when a base accepts H+.

Ca2+

Conjugate acid of strong base Ca(OH)2.

NO3-

Conjugate base of strong acid HNO3.

Strong electrolyte

Dissociates completely in solution, e.g., Ca(NO3)2.

Na+

Conjugate acid of strong base NaOH.

ClO-

Conjugate base of weak acid HClO.

Weak electrolyte

Partially dissociates in solution, e.g., NaClO.

NH4+

Conjugate acid of weak base NH3.

Cl-

Conjugate base of strong acid HCl.

Common-Ion Effect

Shift in equilibrium due to added common ion.

HF

Weak acid, used in common-ion effect example.

HCl

Strong acid, increases [H3O+] in solution.

pH calculation

pH = -log[H3O+], used for acidity measurement.