課程名稱︰物理化學
課程性質︰熱力學三大定律、基本動力學概念、反應動力學、活化能、等..
課程教師︰黃良平
開課學院：生農學院
開課系所︰農化系
考試日期（年月日）︰Oct.18 2007
考試時限（分鐘）：兩節課，中間不下課
是否需發放獎勵金：是
（如未明確表示，則不予發放）
試題 :
1. One mole of an ideal gas undergoes an isothermal expansion at 300K from
1.00 atm to a final pressure while performing 200J of expansion work.
(a) What is the change of the internal energy ΔU of the system?
(b) Does the gas absorb or release heat in this process? How much heat?
(c) If the gas expand against an external pressure of 0.20 atm, is the
process reversible of irreversible? Calculate the final pressure of
the gas.
2. The total pressure of mixture of oxygen and hydrogen is 1.00 atm. The
mixture is ignited and the water is remobed. The remaining gas is pure
hydrogen and exerts a pressure of 4.00 atm when measured at the same values
of T and V as the original mixture in mole precent?
3. Consider the oxidation of the amino acid glycine (NH2CH2COOH) to produce
water, carbon dioxide and urea(NH2CONH2)
NH2CH2COOH(s) + 3O2(g) → NH2CONH2(s) + 3CO2(g) + 3H2O(l)
Calculate the volume of carbon dioxide evolved at P = 1.00 atm and T = 310K
from the oxidation of 0.0100 g of glycine
4. Assume that the molar internal energy os a gas over a temperature range
could be expressed as:
Um(T) = a + bT + cT^2 + dT^3
If the gas also behaves as an ideal gas in this temperature range, find an
expression for the constan-pressure molar hear capacity (Cp,m) at
temperature T.
5. Calculate the pressure exerted by Ar for a molar volume of 1.42 L mol^-1
at 300K using the van der Waals equation of state. The van der Waals
parameters a and b for Ar are 1.355 bad dm^6 mol^-2 and 0.0320 dm^3 mol^-1
respectively. Is the attractive or repulsive portion of the potential
dominant under these conditions?
nRT n^2a
van der Waals equation: P = ------- － --------
V-nb V^2
6. In the adaibatic expansion of 1.00 mol of an ideal gas from an initial
temperature of 25.0 celcius, the work done on the surroudings is 1200J if
Cv,m = 3/2R, calculate q, w, ΔU and ΔH
7. A 1.00-mol sample of an ideal gas for which Cv,m = 3/2R undergoes the
following two-step process:(1)From an initail state of the gas described by
T = 28C and P = 2.00 x 10^4 Pa, the gas undergoes an isothermal expansion
against a constant external pressure of 1.00 x 10^4 Pa until the volume has
doubled. (2) Subsequently, the gas is cooled at constant volume. The
temperature falls -40.5C. Calculate q,w, ΔU and ΔH for each step and for
the overall process.
8. Consider the following experiment. Gas contained ina cylinder is initially
present only on one side of aporous plus that divides the cylinder into
two volumes. The entire system is thermally isolated from its surroudings.
The gas is pushed through the porous plug by the pistons in such a way that
both P1 and P2 are maintained constant but not equal to each other. The
flow is so slow that the gas emerging from the plus is equilibrated at P2,
so P2 can be taken as uniform throughout the expansion on side 2.
(a) First, diagram this experiment. Once you think you have it setup
correctly, see me to confirm
(b) Show that for this throttling process, h1 = h2, where hi is the molar
enthalpy on side i of the composite system
9. The heat capacity of solid lead oxide is given by
Cv,m = 44.35 + 1.47 x 10^-3 T/K in units of J K^-1 mol^-1
Calculate the change in enthalpy of 1.00 mol of PbO(s) if it s cooled
from 500 to 300K at constant pressure.
10.Regard the enthalpy as a function of T and P. Use cyclic rule to obtain
the expression
(δH/δP)下標T
Cp = － ----------------
(δT/δP)下標H
11.Derive the following expresion for calculating the isothermal change in
the constant volume heat capacity:
(δCv/δV)下標T = T(δ^2P/δT^2)下標V
12.The molar heat capacity Cp,m of SO2(g) is described by the following
eauaction over the range 300K < 1700K:
Cp,m
----- = 3.093 + 6.967x10^-7 T/K － 45.81x10^-7 T^2/K^2 + 1.035x10^-9 T^3/K^3
R
In this equation, T is the absolute temperature in Kelvin. The ration
T^n/K^n ensure that Cp,m has the correct dimension. Assuming ideal gas
behavior, calculate q, w ΔU and ΔH if 1.00 mol of SO2(g) is heated from
75C ~ 1350C at a constant pressure of 1.00 bar.
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