Acid/Base Chemistry

Question 1

pH Scale

Answer 1

• Method for expressing hydrogen ion concentration
• pH = -log[H3O+]
• pH = 7 is neutral
• [H3O+] = [OH-]
• Acid: 0-7
• Base: 7-14

Question 2

pKw and pOH

Answer 2

• pOH = -log[OH-]
• pKw = -log(Kw)
• pH + pOH = pKw
• At 25 degrees C pH + pOH = 14

Question 3

pKa and pKb

Answer 3

• pKa = -log(Ka)
• pKb = -log(Kb)
• pKa +pKb = pKw
• At 25 degrees C, pKa + pKb = 14

Question 4

Weak Acid Summary

Answer 4

• Ka = [H3O+][Ac-]/[HAc]

- pKa = -log(Ka)

Question 5

Weak Base Summary

Answer 5

• Kb = [HB+][OH-]/[B]

- pKb = -log(Kb)

Question 6

Solution of One Weak Acid

Answer 6

[H3O+] = (-Ka + sqrt(Ka^2 + 4KaCa))/2

Question 7

Simplified One Weak Acid Solution

Answer 7

-Ca&raquo_space; [H3O+]

[H3O+] = sqrt(KaCa)

Question 8

Solution of One Weak Base

Answer 8

[OH-] = (-Kb + sqrt(Kb^2 + 4KbCb))/2

Question 9

Simplified One Weak Base Solution

Answer 9

-Cb&raquo_space; [OH-]

[OH-] = sqrt(KbCb)

Question 10

Salts

Answer 10

• Weak acid salts behave like a base (NaAc => Na+ + Ac-)

- Weak base salts behave like an acid (Eph * HCl => H+Ephed + CL-)