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Coppin State College
Chemistry 101 Examination #6
Department of Natural Sciences
Chapter 6 (Dr. Amah)
Name ____________________________________________________
Last
First
This examination contains thirty (20) multiple choice questions with five (5) responses.
There is only one correct response for each question. Time: 120 minutes.
1. How many joules are equivalent to 158 calories?
a. 0.0265 J
b. 8.31 J
c. 22.1 J
d. 37.8 J
e. 661 J.
2. Heat capacity is defined as
a. the amount of heat required to raise the temperature of a substance by 1 K
b. the amount of heat required to raise the temperature of 1 grams of substance by
1K
c. 4.18 J/g.K
d. 4.18J/K
e. 4.18 cal/g.K
3. How many calories are equivalent to 364 J ?
a. 1.33 cal
b. 1523 cal
c. 87.0 cal
e. 0.364 cal
4. When two solutions are mixed, the container ‘feels hot.” Thus,
a. the reaction is endothermic.
b. the reaction is exothermic.
c. the energy of the universe is increased.
d. the energy of both the system and surrounding is decreased.
e. The energy of the system is increased.
d. 24.0cal
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5. Which response lists the processes that are endothermic and none that are
exothermic?
1.
2.
3.
4.
Evaporation of water
Sublimation of ice
Condensation of steam
Freezing of water
a. 1 and 2 only
b. 1 and 3 only c. 2 and 3 only
d. 3 and 4 only
e. 2,3, and 4 only.
6. Which process involves the largest energy change for one mole of 1,4dichlorobenzene, moth balls?
a. ▲Hvaporization
b. ▲Hsublimation
c. ▲Hboiling
d. ▲Hfusion
e. ▲Hcondensation
7. Consider the thermal energy transfer process during a chemical process. When heat is
transferred to the system, the process is said to be ________ and the sign of H is _______
a. exothermic, positive
b. exothermic, negative
c. endothermic, positive
d. endothermic, negative
e. enthalpic, negative.
8. For the general reaction 2A + B2  2AB, H is + 50.0 KJ. We can conclude that
a. the reaction is exothermic
b. the surrounding absorb energy
c. the reaction is endothermic
d. the bond energy of each A-B bond is 50.0 KJ
e. the molecule AB contains less energy than A or B2
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9. Calculate the standard enthalpy change for the reaction:
C2H2(g)
+ H2(g)

C2H4(g)
based on the following standard enthalpies of formation:
H0 [ C2H2(g)] = +226.7 KJ/mol
H0 [ C2H4(g)] = +52.3 KJ/mol
H0 [H2(g)]
= 0.0 KJ/mol
b. –56.4 KJ
a. 174.4 KJ
c. –174.4 KJ
d. –279.0 KJ
e. –321.1 KJ
10. Calculate the standard enthalpy of formation of carbon monoxide,
C(s)
+ 1/2O2(g)

CO(g)
given the enthalpies of the reactions given below.
CO2(g)
H0 = -393.5 KJ
2CO(g) + O2(g) 
2CO2(g)
H0 = -566.0 KJ
a. –959.6 KJ
b. –421.6 KJ
C(s) +
O2(g)

c. –172.5 KJ
d. –110.5 KJ
e. 172.5 KJ
11. All of the following statements are true EXCEPT
a. energy is neither created nor destroyed in chemical reactions
b. spontaneous reactions are always exothermic
c. kinetic energy is the energy associated with motion
d. energy is the capacity to do work
e. increasing the thermal energy of a gas increases the motion of its atoms.
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12. If 34.8 J is required to change the temperature of 10.0g of mercury by 25 K, what is the
specific heat of mercury?
a. 0.139 J/g.K
b. 0.338 J/g.KJ
c. 0.718 J/g.K
d. 0.870 J/g.K
e. 1.93 J/g.K
13. If 1.00 mol of H2O at 25 0C absorbs 1.00 KJ of heat, what is the final temperature of the
water? The specific heat of water is 4.184 J/g.K.
a. 11.7 0C
b. 32.9 0C
c. 38.3 0C
d. 52.1 0C
e. 70.9 0C
14. Ethylene glycol has a specific heat of 0.578 cal/(g. 0C). If 23.2 g of ethylene glycol absorbs
75.6 cal of heat energy, what will the final temperature increase be?
a. 0.770C
b. 1.880C
c. 5.640C
d. 1.01 x 103 0C
e. 3.03 x 103 0C
15. When a sample of aqueous hydrochloric acid was neutralized with aqueous sodium
hydroxide in a calorimeter, the temperature of 100.0 g of water surrounding the reaction
increased from 25.0 0C to 31.5 0C. If the specific heat of water is 1.00 cal/(g. 0C), calculate
the quantity of energy in calories involved in this neutralization reaction.
a.
b.
c.
d.
e.
1250 cal
650 cal
1000 cal
100.0 cal
6.50 cal
16. When the cold-pack is activated, a chemical reaction occurs and the temperature of the
pack contents drops sharply. Which of the following is a correct description of the reaction
occurring in the pack?
a. the reaction is exothermic; ▲H0 > 0
b. the reaction is exothermic; ▲H0 < 0
c. the reaction is endothermic;▲H0 > 0
d. the reaction is endothermic; ▲H0 < 0
e. None of the above statements is correct.
17. All of the following statements are true EXCEPT
a.
b.
c.
d.
e.
Energy is neither created nor destroyed in chemical reactions.
Kinetic energy is the energy associated with motion.
Energy is the capacity to do work.
Increasing the thermal energy of a gas increases the motions of its atoms
Spontaneous reactions are always exothermic
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18. All of the following statements are true EXCEPT
a.
b.
c.
d.
e.
In an endothermic process heat is transferred from the surrounding to the system.
The greater the specific heat of an object, the more thermal energy it can store
The SI unit of specific heat capacity is joules per gram per Kelvin
Heat is transferred from the system to the surrounding in an exothermic process.
The temperature of a system is a state function
19. Commercial cold packs consist of solid ammonium nitrate and water. NH 4NO3 absorbs 330
J of heat per gram dissolved in water. In a coffee-cup calorimeter, 3.00g. NH4NO3 is
dissolved in 100.00 g of water at 24.0 0C. What is the final temperature of the solution?
Assume that the total mass of the solution is 103.00 g and has a specific heat of 4.184
J/g.K.
a.
b.
c.
d.
e.
11.0 0C
15.9 0C
19.1 0C
21.7 0C
35.9 0C
20. A chemical reaction in a bomb calorimeter evolves 4.12 kJ of heat. If the temperature of the
calorimeter increases from 18.20 0C to 22.79 0C, what is the heat capacity of the
calorimeter
a.
b.
c.
d.
e.
1.11 kJ/0C
4.12 kJ/0C
4.59 kJ/0C
189 kJ/0C
898 kJ/0C
Q
= Ms x ▲Ts x SHs
▲H
=
H P - HR