Acids and Bases

Strong Acids

SO I Brought NO Clean ClOthes

Strong Bases

Group 1 and 2 OH-, O2-, H-

Buffers

Resists change in pH by having an appreciable ratio of a weak acid-base pair

Requirements for buffers

• Both concentrations are greater than 100x than Ka

• Ratio of WA to WB is between 0.1 and 10

Ways to make a buffer

• Mixing a WA + CWB

• Mixing excess WA + limiting SB

• Mixing excess WB + limiting SA

When a SA is added to a buffer

WB consumed, increasing WA

When SB is added to a buffer

WA is consumed, increasing WB

Titrant

Solution in the burette, usually the stronger one

Analyte

Solution in the beaker

Equivalence Point

Mols are equal (only for monoprotic acids)

If WA + SB titrated, what is the pH?

Basic

If WB + SA titrated, what is the pH

Acidic

What does pH equal to at half equivalence point?

pKa

Buffer Region

±1 pKa

What is the pH of SA and SB at equivalence?

7

Diluted solutions of WA/B

Have higher %ionization

If there’s more H+

HA for dominates, shift L

If there’s less H+

A- form dominates, shift R

H+ stays the same if

[HA] < 100x[buffer]

Protonated form dominates when

pH < pKa

Deprotonated form dominates when

pH > pKa

Amino Acids are made of

Amine + COOH + C + R group