1) A sample of air from a home is found to contain 7.2 ppm of carbon monoxide. This
means that if the total pressure is 695 torr, then the partial pressure of CO is ________
torr.
A) 5.0 103
B) 5.0 10-3
C) 5.0
D) 1.0 104
E) 9.7 107
2) Sulfur and oxygen react in a combination reaction to produce sulfur trioxide, an
environmental pollutant:
2S (s) + 3O2 (g) → 2SO3 (g)
In a particular experiment, the reaction of 1.0 g S with 1.0 g O2 produced 0.80 g of
SO3. The % yield in this experiment is ________.
A) 30
B) 29
C) 21
D) 88
E) 47
3) A sample of C3H8O that contains 200 molecules contains ________ carbon atoms.
A) 600
B) 200
C) 3.61 x 1026
D) 1.20 x 1026
E) 4.01 x 1025
4) The normal boiling point of C2Cl3F3 is 47.6 oC and its molar enthalpy of
vaporization is 27.49 kJ/mol. What is the change in entropy in the system in J/K when
28.6 grams of C2Cl3F3 vaporizes to a gas at the normal boiling point?
A) -13.1
B) -4.19
C) 4.19
D) 13.1
E) 27.5
5) The element X has three naturally occurring isotopes. The masses (amu) and %
abundances of the isotopes are given in the table below. The average atomic mass of the
element is ________ amu.
A) 17.20
B) 16.90
C) 17.65
D) 17.11
E) 16.90
6) Of the following elements, ________ has the most negative electron affinity.
A) S
B) Cl
C) Se
D) Br
E) I
7) How many Significant Figures does the number 0.005000 have?
A) 4
B) 5
C) 1
D) 2
E) 3
8) The energy of a photon that has a wavelength of 13.2 nm is ________ J.
A) 9.55 X 10-25
B) 1.62 X 10-17
C) 1.99 X 10-25
D) 4.42 X 10-23
E) 1.51 X 10-17
9) Nuclei above the belt of stability can lower their neutron-to-proton ratio by
________.
A) beta emission
B) gamma emission
C) positron emission
D) electron capture
E) Any of the above processes will lower the neutron-to-proton ratio.
10) The molecular geometry of ________ is square planar.
A) CCl4
B) XeF4
C) PH3
D) XeF2
E) ICl3
11) What species has the electron configuration [Ar]3d4?
A) Mn2+
B) Cr2+
C) V3+
D) Fe3+
E) K+
12) Round the number 0.007222 to three significant figures.
A) 0.007
B) 0.00722
C) 0.0072
D) 0.00723
E) 0.007225
13) GeF3H is formed from GeH4 and GeF4 in the combination reaction:
GeH4 + 3GeF4 → 4GeF3H
If the reaction yield is 92.6%, how many moles of GeF4 are needed to produce 8.00 mol
of GeF3H?
A) 3.24
B) 5.56
C) 6.48
D) 2.78
E) 2.16