推 srwff:已收精華區 01/22 00:16
課程名稱︰普通化學甲上
課程性質︰系必修兼通識
課程教師︰佘瑞琳
開課學院：
開課系所︰大氣科學系 農業化學系 地質科學系
考試日期（年月日）︰97/1/16
考試時限（分鐘）：110mins(最後又延五分鐘)
是否需發放獎勵金：是
（如未明確表示，則不予發放）
試題 :
R=0.082L-atm/mol-K=8.314J/mol-K;pico-,p=10^(-12)
1.Multiple choices questions(24%)
bc 1.Which of the following molecules is polar?
a.NH4+ b.O3 c.cis-ClHC=CHCl d.SO3
b 2.According to the critical point,which of the following substances cannot
be liquefied as 25C?
a.NH3:132C and 111atm b.N2:-147C and 34atm c.CO2:31C and 72.8atm
d.cannot be determined from critical point
bc 3.Which of the following statements is true?
a.The solubility of solid solutes increases with increasing temprature.
b.The solubility of gaseous solutes decreases with increasing temprature.
c.The boiling poing of seawater is higher than 100C at 1atm
d.The vapor pressure of a solution is directly related to the mole fraction of solute.
acd 4.The following plot shows the vapor pressure of various solutions of
components A and B at certain temprature. Which of the following
statements is true?(圖是下凹狀的蒸氣壓-莫耳分率圖,P0A 較 P0B 低)
a.The solutions exhibit negative deviations from Raoult's law.
b.ΔHmix for the solution should be negative.
c.The intermolecular forces are stronger in solution than in either
pure A or pure B
d.Pure liquid B is more volatile than pure liquid A.
c 5.If the human eye has an osmotic pressure of 8.00 atm at 25C,what concentration
of the solute particles in water will provide an isotonic eyedrop solution?
a.0.00323M b.0.0385M c.0.327M d.3.90M
送分6.
abd 7.For a first order reaction:A→P,the following data were obtained.
time [A](M)
0.0 2.00 a.The average rate of the reaction between 0 and
5.0 2.00 10s is 0.15M/s
10.0 0.50 b.The half life for the reaction is 5.0s
15.0 0.25 c.A plot of 1/[A] versus time is linear
20.0 0.125 d.The rate constant for this reaction is 0.14 1/s
abc 8.For the reaction 2NO2+F2→2NO2F,the experimentally determined rate law is
Rate=k[NO2][F2] A suggested mechanism for the reaction is:
step 1 NO2+F2→NO2F+F slow step 2 F+NO2→NO2F fast
a.Step 1 is the rate determining step
b.The rate law deduced form the mechanism is Rate=k[NO2][F2]
c.This is an acceptable mechanism.
d.F is the catalyst in the reaction.
d 9.The rate constant k for the gas-phase decomposition of N2O5:N2O5→2NO2+
1/2O2 has the following temprature dependence. Calculate the activation
energy of the reaction.(1/T和ln(k)成一回歸直線，y=-12447x+31.519)
T(K) k(1/s) 1/T ln(k)
338 0.0049 0.00296 -5.32
318 0.0050 0.00316 -7.60
298 0.00004 0.00336 -10.26
a.1020J/mol b.12447J/mol c.0.000831kJ/mol d.103kJ/mol
ac 10.Rank the following in order of increasing energy gap:
a.Mg<Si with B<Si<S8 b.S8<Si<Si with B<Mg
c.Mg<Si with B<Si<S8 d.Si with B<Mg<Si<S8
abd 11.Which of the following is the characteristics of nanodiamond?
a.One of the allotropes b.Highly thermally conductive.
c.Use sp2 hybride orbitals to form covalent bonds d.Biocompatible.
c 12.The rate law for the reaction 2NO2+O3→N2O5+O2 is rate=k[NO2][O3]
Which one of the following mechanisms is consistent with this rate law?
a.NO2+NO2→N2O4 fast ; N2O4+O3→N2O5+O2 slow
b.NO2+O3→NO5 fast ; NO5+NO5→N2O5+5/2O2 slow
c.NO2+O3→NO3+O2 slow ; NO3+NO2→N2O5 fast
d.NO2+NO2→N2O2+O2 slow ; N2O2+O3→N2O5 fast
2.Problems(76%)
1.Use the following data to estimate ΔH0f for magnesium fluoride:
Mg(s)+F2(g)→MgF2(s) (6%) (-2088kJ/mol)
Lattice energy -3916kJ/mol
First ionization energy of Mg 735kJ/mol
Second ionization energy of Mg 1445kJ/mol
Election affinity of F -328kJ/mol
Bond energy of F2 154kJ/mol
Enthalpy of sublimation of Mg 150kJ/mol
2.(a)Draw all the resonance Lewis structures of nitrate ion(NO3-)
(b)Determine the formal charges of the atoms in each structure.
A:氮原子 +1 ,氧原子 0,-1
(c)What's the geometry of the ion? A:trigonal planer
(d)Predict the hybridization of central atom. A:sp2
3.Acetic acid can be manufactured using the following reaction:
CH3OH(g)+CO(g)→CH3COOH
(a)Use bond energies to estimate the enthalpy change for the reaction.
(b)Is the reaction endothermaic or exothermic?
(-75kJ,放熱)
4.Using the molecular orbital,(a)draw the energy level diagrams,(b)write
the electron configurations,(c)determine the bond orders,(d)compare the
bond energy,and(e)indicate the magnetic properties(that is diamagnetic
or paramagnetic)for the diatomic species NO,and NO+.(f)Show the HOMO-
LUMO energy gap in NO+.
5.Complete the Lewis structures,showing all lone pairs.Give approximate
values for bond angles of a and b. Give the hybridization of C. How
many σ bonds and π bonds are there in the molecule(丙酮)
6.A certain form of lead (207.2g/mol) has a cubic closest packed(face-
centered cubic) structure with an edge length of 492 pm.(a)Indicate the
coordination number, and (b)how many lead atoms are there in unit cell?
(c)Calculate the value of the atomic radius and the density of lead?
(12,4,11.6g/cm3)
7.The structure of crystalline zinc sulfide is shown below.Calculate the
number of zinc and sulfide ions in the unit cell. The zinc ion is in the
trigonal,tetrahedral or octahedral hole?
(4,4,tetrahedral hole)
8.On the mountain, the atmospheric pressure is 520torr. What is the
boiling point of water(蒸發熱=40.7kJ/mol)?
Hint: ln(Pvap)=-(蒸發熱/RT)+C (90C)
9.A 1.37M solution of citric acid(H3C6H5O7) in water has a density of
1.10g/cm3. Calculate the mass percent,molality,mole fraction,and normality
of the citric acid. Citric acid has three acidic protions.
(23.9%,1.64m,0.0287,4.11N)
10.The vapor pressures of pure ethanol and pure 1-propanol at 35C are 100
mmHg and 37.6 mmHg,respectively. Assume ideal behavior, calculate the
partial pressures of ethanol and 1-propanol at 35C over a solution of
ethanol in 1-propanol,in which the mole fraction of ethanol is 0.300
What is the composition of the vapor expressed as mole fraction?
(30.0mmHg,26.3mmHg;酒精0.533,正丙醇0.467)
11.The decomposition of ethanol on an alumina(Al2O3) surface was studied a
t 600K: C2H5OH(g)→C2H4(g)+H2O(g)
Concentration versus time data were collected for this reaction,and a
plot of [A] versus time resulted in a straight line with a slope of
-4.00*10^(-5) mol/L.s
(a)Determine the rate law,integrated rate law,and the value of the
rate constant for this reaction.(k,[A]=-kt+[A0],4.00*10^(-5) mol/L.s)
(b)If the initial concentration of C2H5OH was 1.25*10^(-2)M,calculate
the half-life for this reaction.(156s)
(c)How much time is required for all the 1.25*10^(-2)M C2H5OH to decompose?
(313s)
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