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Student ID : _________________________
CH 115 Summer 2015 Mock Exam 3
*** Assume that equations are NOT balanced ***
1. Fill in the blank with the correct letter.
1.
___Work
2. ___Thermodynamics
3. ___System
4. ___ Potential Energy
5. ___Heat capacity
6. ___Surroundings
7. ___Kinetic energy
8. ___ Internal Energy (E)
9. ___Enthalpy (H)
a.
b.
c.
d.
e.
f.
g.
h.
i.
Energy due to position.
The energy required to move the temperature of a sample by 1 degree.
The movement of an object against some force.
The part of the universe we single out to study in thermodynamics.
The sum of all kinetic and potential energy of a system.
Energy due to motion.
The science of heat, work, and the transformation between them.
Everything that lies outside the system in thermodynamics.
The heat transferred or lost to the system.
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2. 25g of NaCl is dissolved in 100 mL of water. What is the concentration for this solution?
3. What is the molarity of a 14.7% NaClO3 solution if the density of the solution is 1.09g/mL?
a. 0.138 M
b. 1.51 M
c. 766 M
d. 0.00138 M
e. 0.00151 M
4. A reaction in a bomb calorimeter containing 800g of water causes the temperature of the bomb and
water to rise by 26°C. The bomb has a heat capacity of 287 J/°C. What is the reaction’s ΔE in kj?
a. -4590 kJ
b. 4590 kJ
c. -94.5 kJ
d. 94.5 kJ
e. 961 kJ
5. Using the following bond enthalpies in kJmol-1, determine the energy of combustion for 1 mol gaseous
hexane.
ΔHBE: C-H 412; C-C 347; O-H 464; O=O 498; C=O 805 (for CO2 only); C-O 358
a)
b)
c)
d)
e)
809 kJ kJ
-809 kJ
-3922kJ
3922 kJ
none of the above
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6. Balance the reaction below and use the table below to find the ΔHrxn:
CO(g) + H2(g)  C2H5OH(g) + H2O(g)
Compound ΔH°f (kJ/mol)
CO(g)
-110.5
CO2(g)
-393.5
C2H5OH(g) -235.1
C2H5OH(l) -277.1
H2O(l)
-285.8
H2O(g)
-241.8
a.
b.
c.
d.
e.
-366.4 kJ
-255.9 kJ
-299.9 kJ
366.4 kJ
255.9 kJ
7. What is the molarity of a 4.00% barium bromide solution if the density of the solution is 4.78 g/mL?
a. 0.0135 M
b. 0.0161 M
c. 0.837 M
d. 0.00282 M
e. 0.643 M
8. Target reaction: C4H10 + O2  CO2 + H2O
a. C(s) + H2  C4H10
⍙H=?
⍙H= -103.8 kJ
b. H2 + O2  H2O (g)
⍙H= -241.8 kJ
c. C + O2  CO2
⍙H= -393.5 kJ
3
9. Sr + C + 2 O2 SrCO3(s)
1
⍙H=?
a. Sr + 2 O2 SrO
⍙H= -592 kJ
b. SrO + CO2  SrCO3
⍙H= -234 kJ
c. C + O2  CO2
⍙H= -393.5 kJ
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10. Fill-in-the-blank (1 point per blank, no partial credit)
Write the products of the reactions include stoichiometric coefficients and their phase (s, l, g, aq)
Example:
_1_ CaCO3(s) + _2_ HBr(aq) → _1_ CaBr2 (aq) + _1_ CO2 (g) + _1_ H2O (l)
NOTE: If the stoichiometric coefficient is a “1” you need to write it down to get credit!!!!
___ (NH4)3PO4(aq) + ___ NaCl(aq) → ___ __________ ____ + ___ ________ ____
___ AgNO3(aq) + ___ LiCl(aq) → ___ ______ ____ + ___ ______ _____
__ C3H8(l) + ___ O2(g) → ___ ________ ____ + ___ _______ ____
11. What mass of C2H2 (g) is necessary to completely react with 24.2 L of O2 (g) at 0° C and 1 atm?
a.
b.
c.
d.
e.
11.2 g
28.1 g
26.0 g
34.5 g
none of the above
12. Given 30.0 g of CO2 (g) at 25.0 ° C and 1.00 atm, what is the density of the gas (in g/L)?
a)
b)
c)
d)
e)
0.0408 g/L
1.80 g/L
2.64 g/L
1.23 g/L
not enough information to solve
13. What is the deBroglie wavelength of an H atom travelling at 1.00% of the speed of light?
a.
b.
c.
d.
e.
1.7 x 1015 Hz
0.13 pm
4.9 x 10-19 J
3.0 x 106 m
1.0 kg
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14. A 13.2 L sample of gas initially at 1.40 atm and 26.0°C, is simultaneously heated to 182°C and
compressed to 3.90 L. What is the final pressure?
15. It is known that the pressure from a mixture of gases comes from the pressure exerted by each gas in
the mixture. So, given a mixture of 5.00 g of He(g) and 8.00 g of H2(g) in a 10.0 L container at 15.0°C,
answer the following:
(A) What is the pressure exerted by the He(g)?
(B) What is the pressure exerted by the H2(g)?
(C) What is the total pressure exerted by the mixture?
16. Which statements are false?
X. A C=C bond is shorter than a C-C bond
Y. It takes more energy to break a N=O bond than a N-O bond
Z. In a triple bond, 4 electrons are shared between two atoms
a)
b)
c)
d)
e)
X only
Y only
Z only
X and Z
Y and Z
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17. A sample of a Chlorine gas (Cl2) has a mass of 0.58 g. It has a temperature of 65 oC and has a pressure
of 2660 mm Hg. What is the volume of the gas?
18. How many liters of carbon monoxide gas at 27 oC and 0.247 atm can be produced from the burning of
65.5 g of carbon?
___ C (s) + ___ O2 (g) --> ___ CO (g)
19. A student collects 450 mL of HCl gas at a pressure of 2 atm and a temp of 17 oC. What is the volume of
the HCl at 0 oC and 1140 mm HG?
20. Calculate the unknown quantity in the following measurements of the gas: (2 points)
V1= 80.0 mL T1 = 280 K
V2 = ? mL
T2 = 350 K
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21. Calculate the unknown quantity in the following measurements of the gas: (3 points)
P1= 3.0 atm
V1= 50 mL
P2= 4560 torr V2= ? mL
22. A balloon filled with Helium and Argon has a total pressure of 3800 mm Hg. The PHe= 3 atm. What is
the pressure of Argon?
23. Calculate the unknown quantity in the following:
P1= .0036 atm
V1= 62 mL
T1= 373 K
P2= .0029 atm
V2= 64mL
T2= ? K
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Useful information
c = 2.998 x 108 m/s
h = 6.626 x 10-34 J.s
Ideal gas constant: R=0.0821 L*atm/ K*mol
Ideal gas constant: R=8.314 J/K*mol
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3𝑅𝑇
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