Practice Midterm 1
Examiners: Prof. B. Siwick Name:_________________________
Prof. A. Mittermaier
Prof. J. Schwarcz
INSTRUCTIONS (for the actual Midterm)
1. Enter your student number and name on the computer scorecard
provided, by filling in the appropriate circles. Check that your
scorecard has the correct version number filled in (version 1). If
not, fill that in.
2. This examination comprises 30 questions (14 pages including cover
page and 4 blank pages). All questions are of equal value.
3. Transfer answers to the scantron computer scorecard provided.
4. Both the scorecard and the examination paper will be collected
separately at the end of the examination period.
5. Simple Calculators are allowed, and translation dictionaries. NO
notes or texts are allowed.
6. The Examination Security Monitor Program detects pairs of students
with unusually similar answer patterns on multiple-choice exams.
Data generated by this program can be used as admissible evidence,
either to initiate or corroborate an investigation or a charge of
cheating under Section 16 of the Code of Student Conduct and
NOTE TO INVIGILATORS: At the end of the exam, both scorecards and exam papers should be
collected. Collect scorecards separately. THESE DATA WILL BE PROVIDED ON THE MIDTERM
STP: 0°C and 1 a–23 1 mol gas at STP: 22.4 L
k = 1.38 x 10 J/K 0 K = – 273.15 °C
e = 2.718 1 Pa = 1 N/m2
g = 9.81 m/s 1 atm = 101.3 kPa = 760 Torr
π = 3.14 1 bar = 100,000 Pa = 100 kPa
R = 8.314 J/(mol K) 1 J = 1 kg m /s = 1 kPa L
= 0.08206 L atm /(mol K) 1 mol = 6.02 x 10 molecules
P1 1 P2 2 MP MPV
PV = nRT = d = m =
n1 1 n 2 2 RT RT
1 N 2 3 RT 3 RT
P = mu ek= urms= P = hdg
3 V 2 NA M
Integrated Rate Laws:Arrhquastion:
Order 0: [A] = [A0 - k eA= a
k2 − Ea ⎛⎞11
t - k ln = − ⎜⎟
Order 1: [A] = [A0 e 1 1 2 ⎝⎠
Order 2: 1/[A] = 1/[A0+ kt Standard states for various elements under STP conditions:
Hydrogen: H (g)2 Carbon: C(s, graphite) Nitrogen: N (2)
Oxygen: O (g)2op Cpues) SulpS(u)r: 1) Calculate the height in meters of a column of liquid glycerol (density =1.26 g/cm )
required to exert the same pressure as 760 mmHg (d = 13.60 g/cm ).
a) 8.20 m 3
b) 8.20 × 10 m
c) 0.704 m
d) 44.4 m
e) 70.4 m
2) A mercury manometer is used at a barometric pressure of 100.7 kPa. If the mercury
level at the open end of the manometer is 50 cm higher than the mercury level at the
closed end, as shown, what is the pressure of the enclosed gas?
a) 50 torr
b) 500 torr
c) 1255 torr
d) 150.7 torr
e) 260 torr
3) Which statement regarding a sample of an ideal gas is false?
a) If the pressure is doubled at constant temperature, the volume increases by a
factor of two.
b) If the temperature is doubled at constant pressure, the volume increases by a
factor of two.
c) If the temperature is doubled at constant volume, the pressure increases by a
factor of two.
d) If the volume is doubled at constant temperature, the pressure decreases by a
factor of two.
e) If the number of moles of gas is doubled at constant temperature and pressure, the
volume increases by a factor of two.
4) What volume would be occupied by 4.8 g of oxygen gas (O ) 2t 0.50 atm and 133°C?
a) 10 L
b) 3.3 L
c) 13 L
d) 19 L
e) 6.7 L
5) A 500.0 mL sample of O (g) is at 780 mmHg and 30°C. What will be the new volume
if, with constant pressure and amount of gas, the temperature is decreased to -15°C?
a) 426 mL
b) 587 mL
c) 500 mL
d) 250 mL
e) 437 mL 6) A 4.00 L sample of N (2) at 760 mmHg is compressed, at constant temperature, to
3.20 atm. What is the final gas volume?
a) 950 L
b) 0.771 L
c) 1.25 L
d) 13.1 L
e) 59.6 L
7) A sample of helium gas occupies a volume of 38 L at 780 torr and 25°C. What
volume would the gas occupy at standard temperature and pressure?
a) 25 L
b) 38 L
c) 34 L
d) 40 L
e) 36 L
8) A 5.00 L container of unknown gas at 25.0 °C has a pressure of 2.45 atm. The mass
of the gas is 32.1 g. What gas is in the container?
a) NO 2
b) Cl 2
c) SO 2
d) F 2
e) SO 3
9) Diethyl ether (CH 3H OC2 CH )2was3the first general anesthetic. It was first used in
1846 for surgical procedures. What is the density in g/L of diethyl ether at 27 °C and
a) 2.03 × 10 g/L
b) 3.34 g/L
c) 0.299 g/L
d) 37.1 g/L
e) 2.71 g/L
10)Consider the following reaction:
N2(g) + 3 H2(g) → 2 NH (3)
What volume of NH 3(g) can be produced from 200.0 L of H 2g) if the gases are
measured at 350 °C and 400 atm pressure?
a) 133.3 L
b) 200.0 L
c) 66.7 L
d) 400.0 L
e) 300.0 L 11)How many liters of H ar2 needed to make 327 L of NH by the 3eaction:
N 2g) + 3 H (2) → 2NH (g),3
if the gases are at the same temperature and pressure?
a) 491 L
b) 654 L
c) 218 L
d) 38.5 L
e) 327 L
12)The heat of combustion of several fuels are listed in the table below. On a per gram
basis, which fuel releases the most energy?
Fuel ΔH (kJ/mole)
CH 4g) -890.8
CH 3H(l) 726.1
C3H 8g) 2219.2
b) C 3H 8g)
c) CH (4)
d) H (2)
e) CH O3(l)
13)250.0 g of hot coffee at 95.0 °C are placed in a 0.200 kg mug at 20.0 °C. The specific
heat of the coffee is 4.00 J/g °C, while that of the mug is 0.80 J/g °C. Assuming no
heat is lost to the surroundings, what is the final temperature of the system: mug +
a) 84.7 °C
b) 61.7 °C
c) 76.0 °C
d) 57.5 °C
e) 117 °C
14)Some “beetles” defend themselves by spraying hot quinone, C H O (l), at their
6 4 2
enemies. Calculate ΔH° for the reaction:
C6H 4OH) (2) + H O2(l2 → C H O6(l4 2 2H O(l) 2
Given: C H6(O4) (l) 2 C H O 6l)4+ 2 (g) 2 ΔH°= +177.4 kJ,