Buffers: mixture of a weak acid and its conjugate base or of a weak base and its conjugate acid that maintains a constant pH upon dilution or addition of small amounts of acid or base
Buffer solutions have a limited capacity to keep the pH relatively constant. The buffering will be overcome if so much acid or base is added that the ratio of the concentration of the weak acid or base and its salt changes too much
HA + H2O -> H3O+ + A- A-+ H2O -> AH + OH Don't forget about the age old question of What is the bystander effect in psychology?
Ka= [H3O+][A-]/[HA] Kb= [HA][OH-]/[A-]
pKa= pH – log([A-]/[HA]) where HA is the weak acid and A is the conjugate base pKb= pOH – log([BH+]/[B]) where B is the weak base and BH+ is the conjugate acid
[H3O+] = 10-pH pH = -log[H3O+]
[OH-] = 10-pOH pOH = -log[OH-] If you want to learn more check out What is balint's syndrome?
pH + pOH = 14
Ka = 10-pKa pKa = -log[Ka]
Kb = 10-pKb pKb = -log[Kb]
Kb x Ka = Kw
Kw = 10-14
Kw = [H3O+]water[OH-]water
Acid-Base Titration Curve: A plot of the pH of a solution of acid (or base) versus the volume of base (or acid) added to the solution.
At the half equivalence point, pH = pKa
At the equivalence point, the number of moles of added OH– equals the number of moles of H3O+ originally present or vice versa. If you want to learn more check out What can an aneurysm do to the human body?
Don't forget about the age old question of What is the public goods dilemma?
Useful items to MEMORIZE for Exam III