CHEM 1120 test 2 for spring 2003
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1. For the following reaction:
2N
2
O + O
2
º 4NO
The ∆H
F
= +196.84 kJ mol
!1
and ∆S
F
FF
F
= 594.4 J mol
!1
K
!1
. What is the K at 298 K?
( R = 8.314 J mol
!1
K
!1
)
a. 3,6 × 10
65
b. 3.5 × 10
-4
c. 2.8 × 10
3
d. 2.8 × 10
-66
e. 1.019
2. What is the pH of a 0.50
M
solution of HNO
3
?
a. 0.30 b. 1.30 c. 1.50 d. 13.70 e. 0.50
3. What is the pH of a 0.032
M
solution of NaOH?
a. 12.51 b. 13.07 c. 1.49 d. 11.32 e. 7.00
4. What is the pH of a 0.010
M
solution of Ca(OH)
2
?
a. 1.00 b. 2.00 c. 2.30 d. 12.30 e. 12.00
5. What is the pH of a 0.010
M
solution of HCOOH? (K
a
(HCOOH) = 1.8 × 10
-4
)
a. 11.13 b. 3.74 c. 7.87 d. 6.12 e. 2.87
6. What is the pH of a 0.35
M
solution of NH
3
? (K
b
(NH
3
) = 1.8 × 10
-5
)
a. 11.40 b. 11.63 c. 4.74 d. 2.37 e. 2.60
7. What is the pH of a solution which is 0.20
M
in NaCH
3
COO and 0.050
M
in CH
3
COOH?
(K
a
(CH
3
COOH) = 1.8 × 10
-5
)
a. 5.35 b. 4.14 c. 7.00 d. 9.86 e. 8.65
8. What is the pH of a solution which is 0.10
M
in NH
3
and 0.10
M
in NH
4
Cl? (K
b
(NH
3
) =
1.8 × 10
-5
)
a. 4.74 b. 5.56 c. 7.00 d. 8.35 e. 9.26
9. What is the pH of a solution which is 0.50
M
in CH
3
NH
3
NO
3
? (K
b
(CH
3
NH
2
) = 4.4 × 10
-4
)
a. 6.45 b. 8.52 c. 5.47 d. 1.82 e. 12.17
