L29 - Acids and Bases

Strong/weak Acids and bases Calculating the level of dissociation of acid/bases in solution Polyprotic acid

Acid

Molecular species that can donate protons.

Base

Molecule that can accept protons.

Equilibrium Constant (Ka)

Governs acid dissociation and indicates how much acid will dissociate in water.

Acidity

Measure of H3O+ concentration in a solution.

Hydronium Ion

Ion formed when an acid donates a proton to water (H3O+).

pH Scale

Scale used to compare H3O+ concentrations, typically ranging from 0 to 14.

pOH

Minus log base 10 of the OH- concentration.

Relationship Between pH and pOH

pH + pOH = 14 at 25 degrees Celsius.

Strong Acids and Bases

Acids and bases that fully dissociate in solution due to large equilibrium constants.

H3O+ Concentration (Strong Acid)

Equilibrium concentration of H3O+ should be equal to the amount of HCl that was added initially

Low pH

High H3O+ concentration gives you this on the pH scale.

Acidic Solution

pH less than 7.

Basic Solution

pH greater than 7.

Weak Acid

Acid that only partially dissociates in water, resulting in equilibrium constants much less than one.

pKa

Mathematical operation used to convert Ka values to a more manageable scale.

pKa Formula

Minus log base 10 of the Ka.

pH Calculation

pH = -log[H3O+].

ICE Method

Technique for calculating equilibrium concentrations.

Simplifying Assumption

Assumption that the change (x) is smaller than the initial concentration.

Base Ionization Constant (Kb)

Constant for the reaction of a base with water.

pH and pOH Relationship

pH + pOH = 14.

Ka and Kb Relationship

Important relationship between Ka and Kb is Ka * Kb = Kw.

pKa and pKb

pKa + pKb = 14.

Polyprotic Acid

Acid that can donate multiple hydrogens

Polyprotic Bases

Base that can accept multiple protons