A solution is composed of equal concentrations of

833. A solution is composed of equal concentrations of
aqueous ammonia (pKb=4.74) and ammonium chloride
(pK.=9.26). What would be the pH of the resulting
solution?
A. 4.74
B.
7.00
c.
9.26
D.
The pH of the solution cannot be determined from
the information given
834. An aqueous solution is composed of 2 M ammonia (pKb
= 4.74) and 0.2 M ammonium chloride (pK. = 9.26).
What is the pH of the solution?
A. 4.74
B. 8.26
c.
9.26
D. 10.26
835. An aqueous solution is created from equal amounts of
1
M
HCl (a strong acid) and 0.01
M
sodium chloride.
What is the approximate pH of the solution?
A. 0
B. 1
c.
2
D. The pH of the solution cannot be estimated withou1
the volumes of solution.
836. Which of the following would be an equation that couk
be used to find the pH of a buffer
if
the
pKb
of the base
and the concentrations ofbase and acid are known?
A. pH=
pKb
+log ([base]/[acid])
B. pH=
pKb
+ log ([acid]/[base])
C. pH =
pKb -
log ([base]/[acid])
D. pH = 14-
pKb
+ log ([base]/[ acid])
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1001 Questions in MCAT Chemistry
837. A buffer is made by combining 30
mL
of a 2.0 M acidic
solution with 42.0 grams of its salt. The resulting
solution has a pH of 7.5. If the solution is then diluted
to a total volume of 300
mL,
what will be the new
value of the pH?
A. 6.5
B.
7.5
c.
8.5
D. Cannot be determined from the information given
838. Solution A contains a buffer formed of 2.0 M acetic
acid and 0.8 M potassium acetate. Solution B contains a
buffer formed of 0.2 M acetic acid and 0.08 M
potassium acetate. How do the solutions compare?
A. The pH and buffer capacity of both solutions are
the same
B. The pH of solution A is lower than that of solution
B, but the buffer capacity is the same
C. The pH of solution A is the same as that of solution
B, but solution A has a greater buffer capacity
D.
The pH of solution A is lower than that of solution
B, and solution A has a greater buffer capacity than
solution B
839. An unknown weak acid is titrated with sodium
hydroxide. Which of the following can be determined
from a titration curve?
I.
The initial concentration of the acid
II.
The pKa of the acid
m.
The molecular weight of the acid
A. I only
B. I and II only
C. II and ill only
D.
I, II, and ill
840. A monoprotic weak acid is titrated with a strong base.
At the first equivalence point, the pH will be:
A. less than 7
B.
7
C. more than 7
D.
A choice cannot be made without more
information.
841. A monoprotic weak acid is titrated with a strong base.
In the middle of the first buffer region, the pH will be:
A. less than 7
B.
7
C. more than 7
D.
A choice cannot be made without more
information.
90
Indicators and the End Point