Chapter 16: Reactions Between Acids and Bases Flashcards
titration: a procedure for the determination of the … of one substance by the addition of a measured amount of a second substance
quantity
analyte: substance whose concentration is
being determined
titrant is the substance added to
react with the analyte
(basic procedure for acid-base titrations) 1) a known volume of an acid of … is placed in a flask
unknown []
(basic procedure for acid-base titrations) 2) an indicator solution that changes color in a particular … is added to the acid
pH range
(basic procedure for acid-base titrations) 3) a standard solution of base is added until a … occurs, called the …
color change; endpoint
a titration curve is a graph of the pH of a solution as a function of the
amount of titrant that is added
equivalence point: point in the titration when exactly one mole of base has been added for
each mole of acid present in the sample
inflection point: point at which pH
changes most rapidly
the titration of a strong acid with a strong base shows a … in pH at the equivalence point
sharp change
the titration .., …, and … all influence the equivalence point volume
stoichiometry, concentrations, volumes
buffers are solutions that … when either OH- or H+ ions are added
resist changes in pH
strong acids and bases cannot be used as
buffers
buffered solutions contain either: a weak … and its … or a weak … and its …
acid; salt; base; salt
(buffers) keq for neutralization is … meaning that Keq is … and the reaction goes essentially to ..
1/Ka; large; completion
pH of buffer solutions is generally limited to the vicinity of the
pKa for the acid
buffers are most effective in the range of
pKa +- 1
to make an effective buffer, the concentrations of the weak acid and its conjugate base must be at least
100 times the Ka or Kb
most pH buffers are made from solutions with concentrations that range from
.1 to 1.0 M
concentrated buffers are generally more … than dilute buffers
effective
the effectiveness of a buffer is measured by
buffer capacity
buffer capacity= the amount of strong acid or base needed to change the pH of
one liter of buffer by one unit
acid/salt buffering pairs: salt will contain the …., and the cation of a
anion of the acid; strong base
base/salt buffering pairs: the salt will contain the cation of the …, and the anion of a …
base; strong acid