90年上 周必泰 普通化學甲上期中考part A
開課系所︰化學
Total:200% 3小時
 
A.Questions and definitions (140%)
 
1.Write down the full name of the following elements, compounds or apparatus
  a.Cs, b.KMnO4, c.NaHCO3, d.Cr2O7 2-, e.Fe(NO3)3, f. KBrO3, g.GaN, H.H2SO3,
  i.H3PO4, j.HNO2, k.量筒, l.有刻度之滴定管, m.拋棄式滴管, n.洗瓶, o.定容積三
  角錐形燒瓶.                                                     (2%*15=30%)
 
2.Write down both symbol and full name of the a.Noble gases, b.Alkaline earth
  metal families.                                                  (5%*2=10%)
 
3.Write down both symbol and full name of the transition metals from atomic
  number 21 to 30.                                                      (20%)
 
4.For the van-der Waals equation of the real gas Pobs = nRT/(V-nb) - a(n/V)^2
  a.For the following gases, which has the largest a value, and which has the
    smallest value of b, explain
    He,Ar,CH4,NH3                                                        (3%)
  b.At higher pressure such as >1000 atm pressure calculated from the van-der
    Walls equation shows significant deviation from the observed one.  Give a
    reasonable explanation.                                              (7%)
 
5.Balance the following reactions
  a.Ag(s) + CN-(aq) + O2(g)  Ag(CN)2 -(aq) (in basic condition)
  b.CH3OH(aq) + Cr2O7 2-(aq)  CH2O(aq) + Cr3+(aq) (in acidic condition)
                                                                   (5%*2=10%)
 
6.The distribution of velocities of the particles in an ideal gas is described
   by the Maxwell Boltzman distribution law
  f(u) = 4π(m/(2π kB T))^(3/2) *(u^2)*(e^(-m u^2/2 kB T))
  where u=velocity in m/s
        m=mass of a gas particle in kg
        kB=Boltzman's constant=1.38*10^-23
        T=temperature in Kelvin
 
  Derive the most probable velocity ump (need a detailed derivation)    (10%)
 
7.For an ideal gas the mean free path λ can be expressed as
  λ = 1/(2(N/V)(π d^2))
  where d is the diameter of the gas particle.  Assumung the gas possesses a
  root mean square velocity, calculate the collision frequency in a sample of
  helium gas with a volume of 5.0L at 27C and 3.0atm.  The diameter of a
  helium atom is 50pm., atomic mass=4                                   (15%)
 
8.A sample is a mixture of KCl and KBr.  When 0.1024g of the sample is
  dissolved in water and reacted with excess silver nitrate, 0.1889g of solid
  is obtained.  What is the composition by mass percent of the mixture?
  (atomic mass:K:39, Cl:35, Br:80, Ag=108)                              (15%)
 
9.Vitamin A has a molar mass of 286.4g and has a general molecular formula of
  CxHyE, where E is an unknown element.  If Vitamin A is 83.86% C and 10.56% H
   by mass, what is the molecular formula of Vitamin A?                 (10%)
 
10.The plot of PV/nRT versus P for gases N2, CH4, CO2 and H2 (200K) is shown
   below.  Assign each curve to the corresponding gas(Explanation required)
                                                                        (10%)
 

 

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