→ srwff :化學系已收 07/28 21:23
※ 編輯: syuusyou 來自: 140.112.248.143 (07/30 06:40)
課程名稱︰普通化學甲上
課程性質︰暑修
課程教師︰劉如熹
開課學院：理學院
開課系所︰
考試日期（年月日）︰2009/07/28
考試時限（分鐘）：180
是否需發放獎勵金：是
（如未明確表示，則不予發放）
試題 :
1. Calculate the pH of a solution that is 0.60M HF and 1.00M KF. (10%)
2. Describe how you could separate the ions in each of the following groups by
selective precipitation. (8%)
a. Ag+, Mg2+, Cu2+
b. Pb2+, Ca2+, Fe2+
c. Cl-, Br-, I-
d. Pb2+, Bi3+
3. A buffer is made using 45.0 mL of 0.750M HC3H5O2 (Ka=1.3*10^-5) and 55.0 mL
of 0.700M NaC3H5O2. What volume of 0.10M NaOH must be added to change the
pH of the original buffer solution by 2.5%? (10%)
4. Consider 2.00 mol of a minatomic ideal gas that is taken from state A
(PA=2.00 atm, VA=10.0 L) to state B (PB=1.00 atm, VB=30.0 L) by two
different pathways:
(VC=30.0 L,PC=2.00 atm)
↗ ↘
State A (VA=10.0 L, PA=2.00 atm) State B (VB=30.0 L, PB=1.00 atm)
↘ ↗
(VD=10.0 L, PD=1.00 atm)
Calculate q, w, △E, and △H for both pathways. (10%)
5. What is the difference between △H and △E at constant P? (2%)
6. Consider a sample cintaining 5.00 mol of a monatomic ideal gas that is
taken from state A to state B by the following two pathways:
Pathway one:
PA=3.00 atm 1 PC=3.00 atm
VA=15.0 L ==========> VC=55.0 L
2 PB=6.00 atm
==========> VB=20.0 L
Pathway two:
PA=3.00 atm 3 PD=6.00 atm
VA=15.0 L ==========> VD=15.0 L
4 PB=6.00 atm
==========> VB=20.0 L
For each step, assume that the external pressure is constant and equals the
final pressure of the gas for the gas for that step. Calculate q, w, △E,
and △H for each step, and calculate overall values for each pathway.
Explain how the overall values for the two pathways illustrate that △E and
△H ate state functions, whereas q and w are path functions. (20%)
7. The standard enthalpy of formation of H2O(l) at 298 K is -285.5 kJ/mol.
Calculate the chanhe in internal energy for the following precess at 298 K
and 1 atm:
H2O(l) => H2(g) + 1/2 O2(g) △E=?
(10%)
8. When water is supercooled, it freezes at a temperature below 0.0 C. If
10.9 kJ of heat is released when 2.00 mol of supercooled water at -15.0 C
freezes. Calculate the molar enthalpy of fusion for ice at 0.0 C and 1 atm.
Assume the molar heat capacities for H2O(s) and H2O(l) are 37.5 J/K*mol and
75.3 J/K*mol, respectively, and are temperature independent. (10%)
The following choose the only one answer.
9. Which one of the following statements is false? (5%)
A) The change in internal energy, △E, for a process is equal to the amount
of heat absorbed at constant volume, qv.
B) The change in enthalpy, △H, for a process is equal to the amount of
heat absorbed at constant pressure, qp.
C) A bomb calorimeter measures △H directly.
D) If qp for a process is negative, the process is exothermic.
E) The freezing of water is an example of and exothermic reaction.
10.Which of the following statements is correct? (5%)
A) The internal energy of a system increases when more work is done by the
system than heat is flowing into the system.
B) The internal energy if a system decreases when work is done on the
system and heat is flowing into the system.
C) The system does work on the surroundings when an ideal gas expands
against a constant external pressure.
D) All the statement are ture.
E) All the statement ate false.
11.Which statement is true of a process in which 1 mol of a gas is expanded
from state A to state B? (5%)
A) When the gas expands from state A to state B, the surroundings are doing
work on the system.
B) The amount of work done in the process must be the same, regardless of
the path.
C) It is not possible to have more than one path for a change of state.
D) The final volume of the gas will depend on the path taken.
E) The amount of heat released in the process will depend on the path
taken.
12.Two metals of equal mass with different heat capacities are subjected to
the same amount of heat. Which undergoes the smaller change in temperature?
(5%)
A) The metal with the higher heat capacity.
B) The metal with the lower heat capacity.
C) Both undergo the same change in temperature.
D) To determine this, you need to know the initial temperature of the
metals.
E) To determine this, you need to know which metals you are talking about.
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