台灣大學93年第一學期; 期中考(佔學期總分30%);日期: 2004/11/10 (星期三)
課程名稱:普通化學(課程編號203-101A1/A2 班次04、05、06)

     PV = nRT,  R = 0.08206 L‧atm‧K-1‧mol-1 = 8.3144 J‧K-1‧mol-1,
     0℃ = 273 K
     Atomic mass: H = 1.008, He = 4.00, C = 12.01, N = 14.01, O = 16.00,
     Na = 22.99, Cr = 52.00, Fe = 55.85,
     ZA = A‧(N/V)‧[RT/(2πM)]1/2

(1)  Perform the following calculations, and give answers with the proper
     number of significant figures.  (3%)
     (a) 65 + 31.3 – 9.2, (b) (1.5 x 8.56) / (0.08206 x 273),
     (c) 4.1 x 6.022 x 1023.

(2)  Write formula for each of the following compounds, ions, or elements:(10%)
     (a) sulfur trioxide, (b) ammonium sulfate, (c) permanganate ion,
     (d) potassium dihydrogen phosphate, (e) manganese(II) hydroxide,
     (f) chromium(III) carbonate, (g) silicon tetrachloride,
     (h) nitric acid, (i) ozone, (j) neodymium ion (III)

(3)   Name each of the following compounds:   (20%)
     (a) H2S, (b) (NH4)2SO4, (c) O2F2, (d) H2SO4, (e) K2Cr2O7, (f) MgO,
     (g) NO, (h) NH3, (i) NaHCO3, (j) CO2, (k) UF6, (l) NaOCl, (m) BaCrO4,
     (n) HCN, (o) Ca(OH)2, (p) Mg3(PO4)2, (q) CuI, (r) KClO3, (s) Ga2O3
     (t) element-108.

(4)  What is a mass spectrometer? What are the major components of a
     mass spectrometer? (5%)

(5)   Potassium chromate is produced by the reaction of solid chromite ore
      (FeCr2O4) with solid potassium carbonate and gaseous oxygen at
      high temperatures. The other products of the reaction are
      solid iron(III) oxide and gaseous carbon dioxide.
      In a particular experiment 169 kg of chromite ore, 298 kg of
      potassium carbonate, and 75.0 kg of oxygen were sealed in a
      reaction vessel and reacted at a high temperature. The amount of
      potassium chromate obtained was 194 kg. Calculate the percentage yield
      of potassium chromate.  (6%)

(6)  What acid and what strong base would react in aqueous solution to produce
     the following salts in the molecular equation? Write the balanced
     molecular equation for each reaction.  (6%)
     (a) potassium perchlorate, (b) cesium nitrate, (c) calcium iodide

(7)  Assign oxidation states to all atoms in each of the following compounds.
     (a) XeOF4, (b) SF4, (c) CO, (d) Fe3O4, (e) Li3N, (f) NO, (g) N2  (7%)

(8)  A student added 50.0mL of an NaOH solution to 100.0 mL of 0.400 M HCl.
     The solution was then treated with an excess of aqueous
     chromium(III) nitrate, resulting in formation of 2.06 g of precipitate.
     Determine the concentration of the Na OH solution.  (6%)

(9)  Mixtures of helium and oxygen are used in scuba diving. What are :  (6%)
     (a) the mole fractions of the two gases
     (b) their partial pressures
     (c) the total pressure in a mixture of 1.96 g He and 60.8 g O2
         confined in a 5.00-L tank at 25.0 °C?

(10) What is a thermocouple wire for temperature measurement? Briefly
     describe its working principle. (4%)

(11) Briefly describe possible methods for measuring the pressures at about:
     (1) 1000 Torr and (2) 1 x 10-7 Torr.
     [Hint: Making simple sketches and pointing out each component of the
            devices may be helpful for interpretation.]  (10%)

(12) What are the four principal assumptions of the kinetic molecular theory
     for ideal gas particles? (4%)

(13) (a) Under what pressure and temperature conditions, a real gas will
         exhibit behavior that is close to ideal behavior?
         (low, moderate, high) (2%)
     (b) In van der Waals’s equation,
         {P + (n2a / V2)}(V - nb) = nRT
         what properties of real gas particles are the constants “a” and
        “b” related to? (2%)

(14) Neglecting intermolecular collisions, calculate the impact rate on a
     400.0 cm2 section of a vessel containing oxygen gas at a pressure of
     1.00 atm and 27 ℃. (4%)

(15) A compound contains only C, H, and N. It is 58.51% C and 7.37% H by mass.
     Helium effuses through a porous frit 3.20 times faster than the compound
     does. Determine the empirical and molecular formulas of this compound.(4%)

(16) The average distance that a molecule travels between collisions is
     called its “mean free path, l”. If one knows that l = 50 m at a
     pressure of 1 x 10-6 Torr for a N2 molecule, what is the mean free path
     for the N2 molecule near you? (4%)