Honors Chemistry
Name: _______________________________________ Date: ________________ Mods: _________
Chapter 17 Test Review
17.1: The Common-Ion Effect
1. When a ______________ electrolyte is added to a solution of weak acid which shares a common ion,
the extent of ionization of the weak acid is ______________________. According to Le Chatelier’s
principle, this causes the equilibrium for the dissociation reaction to shift to the ______________,
resulting in a _______________ in [H+]. In turn, the pH of the solution _______________.
2. When a ______________ electrolyte is added to a solution of weak base which shares a common ion,
the extent of ionization of the weak base is ______________________. According to Le Chatelier’s
principle, this causes the equilibrium for the dissociation reaction to shift to the ______________,
resulting in a _______________ in [OH-]. In turn, the pH of the solution _______________.
3. Calculate the pH of a solution that is 0.085 M lactic acid (HC3H5O3; Ka = 1.4 x 10-4) and 0.05 M sodium
lactate (NaC3H5O3).
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17.2: Buffered Solutions
1. A buffered solution is made from a ___________ conjugate acid-base pair. It is crucial that the acid
and base that make up the buffer do not ___________________ each other. Therefore, a buffer
should be made from a weak acid and a __________ of that same acid.
2. Buffers are particularly ___________________ to pH changes. When a strong acid is added to a
buffered solution, the _____________________ ___________ component of the buffer reacts with the
added strong acid. Therefore, the addition of the strong acid ______________ the conjugate base
concentration and _________________ the weak acid concentration.
When a strong base is added to a buffered solution, the ______________ _____________ component
of the buffer reacts with the added strong base. Therefore, the addition of the strong base
____________________ the weak acid concentration and __________________ the conjugate base
concentration.
3. The amount of acid or base a buffer can neutralize before the pH begins to change appreciably is
called the buffer ___________________.
4. The pH range for a buffer is the range of pH values over which the buffer acts ______________.
5. The best buffer is one in which the moles of the weak acid are _____________ to the moles of its
conjugate base, meaning that the pKa value is identical to the ________ value.
6. Calculate the Ka of a buffer that is 0.72 M in lithium nitrite and 4.64 x 10-4 M in nitrous acid if the pH is
5.15.
7. How many grams of sodium cyanate (NaCNO) should be added to 1.25 L of 0.54 M cyanic acid
(HCNO; Ka = 3.5 x 10-4) to produce a pH of 4.25. Assume that no volume change occurs when the
NaCNO is added to the solution.
8. Calculate the pH of a buffer composed of 0.23 M hydrofluoric acid (HF; Ka = 6.8 x 10-4) and 0.41 M
potassium fluoride (KF).
4.6: Titrations and Solution Stoichiometry
1. A ____________________ is an experimental technique used to determine the concentration of a
solution with an unknown molarity.
2. The solution of unknown concentration which is being titrated is referred to as the ________________.
The solution of known concentration is referred to as the ________________ or the standard solution.
3. The equivalence point of a titration is the point at which ______________________ occurs and there
are _______________ quantities of acid and base present in the solution.
4. True or False: The equivalence point of a titration always occurs at a pH of 7.
5. If it takes 36.50 mL of 1.85 M potassium hydroxide solution to neutralize 125.2 mL of phosphoric acid,
what is the concentration of the phosphoric acid?
6. Nitrous acid is neutralized with calcium hydroxide. A sample of 0.95 g of nitrous acid reacts with 68.4
mL of base. Determine the concentration of the calcium hydroxide.
17.3: Acid-Base Titrations
1. Name and describe the 4 regions of a titration curve.
2. Sketch a curve for each titration below and label the characteristics that distinguish it from the others.
a) Sulfurous Acid titrated with Lithium Hydroxide (standard solution)
b) Sodium Hydroxide titrated with Hydrochloric Acid (standard solution)
c) Nitric Acid titrated with Calcium Hydroxide (standard solution)
d) Ammonia titrated with Perchloric Acid (standard solution)