CHM 100                                             Final Exam                                                           Fall, 1998

 

c = 3 x 108 m/s; h = 6.63 x 10-34 J*s; R = 2.18 x 10-18 J

1 Atm = 760 Torr = 76 cm Hg = 14.7 PSI = 101,300 Pa

R = 0.082 L Atm/mol K,  OR  R = 8.314 J/mol K

NA = 6.02 x 1023

1 amu = 1.6 x 10-27 kg

 

Please enter your Social Security Number on the answer sheet with #2 pencil, and select one answer for each of the following questions.

 

1.  According to the definition of chemistry that we agreed upon in lecture, which of the following statements concerns the chemistry of LSD?

 

a. The chemical LSD tastes sour.

b. The fact that LSD produces hallucinogenic effects proves that thoughts are chemical processes.

c. The symmetry of the LSD molecule is such that it may act as a neural transmitter molecule like the natural transmitter serotonin.

d. The dosage of chemical LSD is typically 10 to 100 milligrams.

e. LSD causes cell damage in rats, but the evidence for such damage in humans

is ambiguous.

 

 

2.  What is the length of the row of dashes (-)'s below as properly measured by

the ruler below it, and what is the error and precision of the measurement?

 

-------------

|        |        |        |

0     .1      .2      .3   units

 

Choice             Length              Error                Precision

a.                     0.2                   0.05                 25%

b.                     0.19                 0.05                 26%

c.                     0.190               0.005              2.6%

c.                     0.19                 0.005              2.6%

e.                     0.200               0.005               2.5%

 

3.  HCl is a mixture of hydrogen and chlorine. a. T                              b. F

 

 

4.  The result of dividing 105 m-1 by 1010 m-3 is:

 

a.  1015 m-4   b.  10-5 m-4    c. 105 m2       d. 10-5 m2      e. 10-5 m4

 

5.  The standard deviation is a measure of

a.  The accuracy of the data

b.  The deviation of the mean from the true value

c.  The deviation of the best value from the mean

d.  The range that measurements span

e.  The standard accuracy of a measuring device.

 

6.  Which measurement definitely has 3 significant figures?

a. 300 km      b.  .003 km     c.  0.300 km    d. 3 x 103 km   e. none of these

 

7.  The density of water at 4oC is 1.00 g/cm3.  What is this density in pounds per cubic inch, given 1 pound = 454 g and 1 inch = 2.54 cm?

a. 0.0361      b. 0.00560      c. 0.0142       d. 27.7         e. 3.72

 

 

 

 

 

8.  How many significant figures should be in the result of subtracting 4.4 from 11, then dividing the result by 0.033?

a. 1                  b. 2                  c. 3                  d. 4                  e. 5

 

9. An element found in another universe consists of two isotopes which are characterized in the chart below.  What is the atomic weight of the element [XI] ?

 

    Isotope    Abundance       Nuclidic Mass

 

      10044à       85.00%          99.80 amu

 

      10244à       15.00%         101.90 amu

 

 

 

 

 

 

 

 

 

a.  100.1      b. 100.6        c. 100.9        d. 101.1        e. 101.3

 

10.  For the nuclide 10044Ru 2+ ,              

a. The atomic mass is 100 amu.

b. The mass number is 44.

c. The number of electrons is 56.

d. The number of neutrons is 44.

e. There are 142 particles (neutrons, protons, electrons)

 

11.  Which of the following particles is deflected most by a magnetic field?

a. gamma photon          b. electron        c. 35Cl+        d. 4He 2+   e. neutron

 

12.  Nuclear matter (particles constituting the nucleus) represents

 

a.  about 99.9% of the volume of an atom

b.  about 1% of the volume of an atom

c.  about 10-4% of the mass of an atom

d.  about 10-12% of the mass of an atom

e.  none of the above

 

13.  If the isotope 20984Po  undergoes beta decay, the product is

 

a.  20983Bi    b. 21084Po      c. 21184Po      d. 20985At      e. 21085At

 

 

 

 

14.  When 105B is bombarded with a proton, it emits an alpha particle and

 

a.  73Li       b. 96C          c. 104Be        d. 94Be         e. 74Be

 

 

 

 

15.  Which particle is the least penetrating?

 

a.  beta       b.  gamma       c.  Xray        d.  alpha

 

 

16.  Which of the following nuclides is most likely to be stable?

 

a. 9140Zr      b. 9441Nb       c. 9641Nb       d.  9040Zr

 

 

17.  The mass of a nucleus is equal to the sum of the masses of the protons and

neutrons which constitute it.

    a. T       b. F

 

 

18.  What is the percent carbon in sucrose, C12H22O11?

a. 3.5%        b. 17%          c. 36%          d. 42%          e. some other percentage

 

 

 

 

 

 

 

19.  What is the empirical formula for a substance that is 57.1% carbon, 38.1% oxygen, and 4.8% hydrogen?

a. CHO         b. CH2O         c. C2H2O        d. CH2O2        e. C3H2O

 

 

 

 

 

 

 

 

 

 

Questions 20, 21, and 22   refer to the reaction of Fe2O3 with CO:

 

    Fe2O3  +  3 CO ---->     2 Fe  +  3 CO2

 

 

 

 

 

 

 

 

 

20.  If 0.15 mol of CO is consumed by an excess of Fe2O3, how much Fe, in moles, will be produced?

 

a. 0.050       b. 0.10         c. 0.20         d. 0.15         e. none of these

 

 

21.  How much CO (in mol) is needed to react with 32 g of Fe2O3?

a. 60 mol      b. 20 mol       c. 0.20 mol     d. 0.60 mol     e. 0.120 mol

 

 

 

22.  If 0.20 mol of Fe2O3 and 0.50 mol of CO are allowed to react, what amount, in mol, of Fe will be produced?

 

a. 0.27 mol    b. 0.30 mol     c. 0.33 mol     d.  0.50 mol    e. .70 mol

 

 

 

 

 

 

23.  How much heat (in kJ) is required to raise the temperature of 250 g of copper, with a specific heat (heat capacity) of 0.75 J/gC, from 20 to 50oC?

 

a. 5.6 kJ      b. 3.8 kJ       c.  0.585 kJ    d. 0.334 kJ     e. 0.125 kJ

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

24.  Given:  H2S(g)  +  3/2 O2(g) ®    H2O(1)  +  SO2(g)       DH = -562.6 kJ

 

             CS2(l)  +  3 O2(g) --->    CO2(g)  +  2 SO2(g)             DH = -1075.2 kJ

 

 

 

 

 

 

     Calculate  DH for the reaction

 

             CS2(l)  +  2 H2O(l) --->     CO2(g)  +  2 H2S(g)

 

a. -1587.4 kJ  b. 1637.8 kJ    c. 512.6 kJ     d. -512.6 kJ    e. 50.0 kJ

 

25.  What mass of KCl is required to prepare 300 mL of a 0.34 M solution?

a. 0.045 g     b. 3.4 g        c. 7.6 g        d. 11.2 g       e. 15.2 g

 

 

 

 

 

 

26.  What volume of 14.7 M (concentrated) H3PO4 should be used to prepare 125mL of 0.42 M solution?

 

a. 25.5 mL     b. 3.6 mL       c. 15.8 mL      d. 31.7 mL      e. 6.9 mL

 

 

 

 

 

 

 

 

27.  What is the frequency in s-1 of a photon with a wavelength of 400 nm?

a. 2.14 x 105                b. 4.7 x 103      c. 4.2 x 1011     d. 420              e. 7.5 x 1014

 

 

 

 

 

 

28.  Because electrons are quantized in the field of a nucleus:

    a. They can absorb any quantity of light.

    b. Transitions between two level produce white light.

    c. They may exist at one energy, then a higher energy, but never at an energy in between.

    d. They can absorb photons of any wavelength.

    e. They produce a continuous spectrum.

 

 

29.   How much energy (in J) is required to promote an electron from the 1st main level to the 10th main level of a hydrogen atom?

 

a.  1.96 x 10-18             b.  2.16 x 10-18             c.  6.33 x 10-19             d.  8.52 x 10-20             e.  3.97 x 10-21

 

 

 

30. The absorption line with the shortest wavelength would result from the transition from

 

a.  n=1 to n=4 

b.  n=3 to n=4

c.  n=2 to n=4

d.  n=3 to n=4

e.  n=2 to n=3

 

 

31.  If the levels of an atom are filled and the 3rd main level of an atom has 6 electrons, what is the total number of electrons in all the levels of the atom?

 

a. 12          b. 14           c. 16           d. 18           e. 22

 

 

32.  Which of the following is the correct electronic configuration (in orderof increasing energy of subshells)  for 39Y?

 

a. 1s22s22p63s23p64s24p64d105s25d1                 b. 1s22s22p63s23p63d104s24p64d3

 

c. 1s22s22p63s23p64s24p64d105s25d1                       d. 1s22s22p63s23p64s23d104p65s24d1

e. none of the above

 

33.  Which of the following atoms has the highest ionization potential?

a. Na          b. Mg           c. Ca           d. Sr           e. Ba

 

34.  Which of the following atoms is largest in volume?

a. Ga          b. In           c. Sn           d. Sb           e. Te

 

 

35.  Which of the following does not have a planar triangular geometry around the underlined atom?  Draw Lewis Structures for clues.

 

a. PCl3        b. H2CO         c. AsF2+        d. SO2          e. NO3-

 

 

 

 

36.  How many electrons are there in the correct Lewis Structure for H2S?

 

a. 4           b. 6            c. 8            d. 10           e. None of these

 

 

 

37.  The bond angle in H2S is closest to

 

a. 90o         b. 109o         c. 120o         d. 180

 

 

 

38.  In the correct Lewis Structure for H2NNH2 , how many total bonding electrons, and total nonbonding electrons  (in lone pairs) are there?

 

            Bonding electrons         nonbonding electrons

a.         10                                4

b.         8                                  6

c.         8                                  4

d.         6                                  4

e.         none of these

 

 

 

 

39.  Which of the following gases has significant intermolecular forces of attraction, and  thus deviates most from ideal gas behavior?

a. NH3         b. CH4          c. O2           d. He           e. F2

 

 

 

 

40.  What is the correct formula for strontium phosphide?

a. SrP         b. Sr2P         c. Sr3P2        d. Sr2P3        e. SrP2

 

 

41.  Which of the following would be most soluble in the nonpolar solvent

benzene?

a. CaCl2       b. H2O          c. Cl2          d. HF           e. KNO3

 

 

42.  Which of the following has the highest percent ionic character?

a. N2          b. NO2          c. FeI3         d. BeCl2        e. RaF2

 

 

43.  Which is the correct Lewis Structure of lithium sulfide?

 

a. [Li+]2[:S:2- ]               b. Li : S : Li                  c. [Li:+][:S:-]      d. [Li2+][:S:2-]                e. [Li:][:S:][:Li]

 

44.  What amount, in moles, of a gas is contained in a 300 mL vessel at 300oC and a pressure of 72 cm Hg?  R = 0.082 LAtm/molK

a. 0.006 mol                 b. 0.46 mol                   c. 0.0012         d. 6.1               e. 1.2 x 10-5

 

 

 

 

 

 

 

 

45.  A mercury manometer is used to measure the pressure of gas

in a flask (as shown in the figure to the right) on a day

when atmospheric pressure is 74 cm Hg.  The heights of the

mercury colums are 11 and 13 cm, as shown on the diagram.

What is the pressure in the flask?

 

a. 76 cm Hg    b.  72cm Hg     c. 87 cm Hg     d. 63 cm Hg    

e. 85 cm Hg

 

 

46.  What is the partial pressure of butane (in cm Hg) in a syringe if 10 mL of

butane is added at 76 cm Hg pressure, then 17 mL of freon is added (to give a

total volume of 27 mL and total pressure of 76 cm Hg?

 

a. 28          b.  32          c. 46           d. 76           e. 205

 

 

 

 

 

47.  If the velocity of a helium atom at a particular temperature is 400 m/s, what will the velocity of a xenon atom be at the same temperature (on the average)?

a. 12 m/s      b. 4.8 x 103 m/s                c. 5.2 x 106 m/s           d. 70 m/s           e. 120 m/s

 

 

 

 

 

48.  Which of the following symbols does not appear in the net ionic equation for the reaction between strongly conducting solutions of H2SO4 and Ba(OH)2 to give a white precipitate? 

a.  H3O+                       b.  BaSO4                    c.  Ba(OH)2                  d.  SO42-                       e. H2O

 

 

49.  Which processes are generally favorable (release energy) in the formation of an ionic compound?

 

a.  Ionization Potential and Electron Affinity

b.  Dissociation energy and Electron Affinity

c.  Sublimation energy and lattice energy           

d.  Ionization Potential and lattice energy

e.  Electron Affinity and Lattice Energy

 

50.  Why does "Magic Sand" form geometric shapes when it is dropped into water?

    a. Because Magic Sand forms ionic bonds with itself.

    b. Because Magic Sand is very polar.

    c. Because Magic Sand carries an electrostatic charge.

    d. Because granules of Magic Sand are of unique geometry.

    e. Because water is polar.