Understanding Acids, Bases, and Buffers

Concentration

Amount of solute in a solution.

Dissociation

Process of breaking into ions in solution.

Equilibrium Constant (Ka)

Ratio of products to reactants for weak acids. [products]/[reactants]

pH Scale

Measures acidity or basicity of a solution.

-can change for water, essentially nuetral is where pH = pOH

when can you know that the pH of water will change

the pH of pure water only changes with pure water

Strong Acid

Completely dissociates in solution.

-has a large Ka

-100% disociation

Weak Acid

Partially dissociates in solution.

weak base

partially dissociates in solution

Kb =

[porducts]/[reactions]

pKb

Negative logarithm of the base dissociation constant.

pKa

Negative logarithm of the acid dissociation constant.

-this will be smaller for stronger weak acids+-

types of acids?

strongers to weakest:

-conc strong

-conc weak

-dilute strong

-dilute weak

Buffer

Resists changes in pH upon acid/base addition.

Hydronium Ion (H3O+)

Ion formed when water accepts a proton.

pOH

Measures hydroxide ion concentration in solution.

Kw

Ion product constant for water at 25°C.

Kb*Ka

Neutral Water

Pure water with pH of 7 at 25°C.

Dissociation Constant

Equilibrium constant for acid-base reactions.

Buffer Capacity

Ability to maintain pH upon addition of acids/bases.

Logarithmic Scale

pH and pOH are logarithmic measures.

Acid-Base Reaction

Reaction between an acid and a base.

Hydroxide Ion (OH-)

Ion that increases basicity in a solution.

Strong Base

Completely dissociates in water.

Weak Base

Partially dissociates in water.

Acid-Base Indicator

Substance that changes color at specific pH.

pH Indicator

Used to determine the pH of a solution.

Titration

Technique to determine concentration of an unknown solution.