chapter 17 - buffers

Question 1

what’s the common-ion effect?

Answer 1

when a weak electrolyte and a strong electrolyte containing a common ion are together in solution, weak electrolyte ionizes less than it would if it were alone in solution

Question 2

what do buffered solutions contain?

Answer 2

a weak conjugate acid-base pair and resist drastic changes in pH when small amounts of strong acid/base are added to them; will not move the concentration/equilibrium too much

Question 3

how are buffers prepared?

Answer 3

mixing a weak acid or base w/ a salt of THAT acid or base; or mixing a salt of a weak acid or base w/ a strong acid or base

Question 4

if H3O is added to a weak acid equilibrium…

Answer 4

reaction shifts to reactant acid, strong acid makes weak acid re-form

Question 5

if OH- is added to a weak base equilibrium…

Answer 5

reaction shifts to reactant side, strong base makes the weak base re-form

Question 6

equation for OH- (NOT ON EXAM)

Answer 6

OH- = Kb (base/acidic salt)

Question 7

equation for H+

Answer 7

H+ = Ka(Acid/basic salt)

Question 8

henderson-hasselbalch equation for pH

Answer 8

pH = pKa + log(basic salt/acid)

Question 9

henderson-hasselbalch equation for pOH

Answer 9

pOH = pKb + log(acidic salt/base)