Name Date
c = 3.00 x 10
8
m/sec h = 6.63 x 10
-34
Js m p
= 1.67 x 10 -24 g (mass of proton)
Rydberg Constant (R
H
) = 2.18 x 10
-18
J
(1) If  H = -65 kJ for a certain process, that process a) requires a catalyst b) occurs rapidly c) is endothermic d) cannot occur e) is exothermic
(2) The sign of  H for the process NaCl(s) -----> NaCl(l) is a) negative, and the process is exothermic b) negative, and the process is endothermic c) positive, and the process is endothermic d) positive, and the process is exothermic e) impossible to predict
(3) How much heat is gained by nickel when 500 g of nickel is warmed from
22.4 to 58.4°C? [The specific heat of nickel is 0.444 J/(g °C)] a) 2000J b) 4000J c) 6000J d) 8000J e) 10000J
CHE 106 Fall Exam #2 1

(4) Which of the following statements is/are correct?
I. The reaction vessel (surroundings) cools when an endothermic reaction occurs.
II. An exothermic reaction is characterized by a positive value of  H.
III. If heat is absorbed by a system, the sign of H is positive a) I b) II c) III d) I and III e) I and II
(5) Which of the following statements is/are correct?
I. When heat energy flows from a system to the surroundings, we know that the
temperature of the system is greater than that of the surroundings.
II. Given the thermochemical equation 4NH
3
(g) + 5O
2
(g) ------> 4 NO(g) + 6H
2
O(g)
 H = -906 kJ, the thermochemical equation for the following reaction is
NO(g) + 3/2H
2
O(g) ------> NH
3
(g) + 5/4O
2
(g)  H = -227 kJ
III. If a reaction has a very large negative value of  H, then the reaction is exothermic a) I b) II c) III d) I and II e) I and III
(6) Given the thermochemical equation for the combustion of propane gas:
C
3
H
8
(g) + 5 O
2
(g) ------> 3 CO
2
(g) + 4 H
2
O(g)  H = -2043 kJ
Calculate the number of grams of propane (C
3
H
8
) you need in order to produce 369 kJ of heat. a) 5.54 g b) 6.50 g c) 7.22 g d) 7.96 g e) 10.1 g
CHE 106 Fall Exam #2 2

(7) Calculate the standard enthalpy change for the following reaction, using the standard
enthalpies of formation given below:
2 CO(g) + O
2
(g) ------> 2 CO
2
(g)
 H f
° (kJ/mol)
C(g)
C(graphite)
715.0
0
CO(g)
CO
2
(g)
-110.5
-393.5 a) -283 kJ b) -566 kJ c) -676 kJ d) +566 kJ e) +283 kJ
(8) What is the molar heat capacity of heptane, C
7
H
16
, if its specific heat is 2.25 J/(g°C)?
(Think and use FLM) a)
175 J/(mol °C) b)
200 J/(mol°C) c)
225 J/(mol°C) d)
250 J/(mol°C) e) 300 J/(mol°C)
(9) All the following have a standard enthalpy of formation value of zero at 25° C and
1.00 atm except a) Ne(g) b) F
2
(g) c) C(s) d) Fe(s) e) CO(g)
CHE 106 Fall Exam #2 3

(10) Given the following data:
N
2
(g) + 3/2 O
2
(g) ------> N
2
O
3
(g)
N
2
(g) + O
2
(g) ------> 2 NO(g)
½ N
2
(g) + O
2
(g) ------> NO
2
(g)
What is  H for the reaction
N
2
O
3
(g) ------> NO(g) + NO
2
(g) a) -207.1 kJ b) -39.7 kJ



H = 83.7 kJ
H = 180.4 kJ
H = 33.2 kJ c) 24.3 kJ d) 39.7 kJ e) 207.1 kJ
(11) Calculate the enthalpy change,  H° rxn
, for the combustion of C
3
H
6
(g):
C
3
H
6
(g) + 9/2 O
2
(g) ------> 3 CO
2
(g) + 3 H
2
O(l)
 H f
° values in kJ per mole are as follows: C
3
H
6
(g) = 21; CO
2
(g) = -394; H
2
O(l) = -286 a) -2061 kJ b) -2019 kJ c) -701 kJ d) 2019 kJ e) 2061 kJ
(12) Which of the following orbital representations is/are allowed?
I. 3s
II. 3p
III. 3d a) I b) II c) III d) I and II e) All three
CHE 106 Fall Exam #2 4

(13)
Passing steam over hot charcoal at 1000°C produces an industrially important mixture of carbon monoxide and hydrogen gases referred to as water gas. The  H° for the water-gas reaction may be calculated from the data for the following reactions;
(1) C(s) + H2O(g) CO(g) + H2(g) (Water Gas Rxn)
(2) C(s) + O2(g)
(3) 2 H2(g) + O2(g)
(4) 2 CO(g) + O2(g)
CO2(g)
2 H2O(g)
2 CO2(g)



H° = -393.5 KJ
H° = -483.6 kJ
H = -566.0 kJ
Which expression represents the correct  H for the water-gas reaction (rxn 1)? a)  H(rxn 1) =  H(rxn 4) -  H(rxn 3) -  H(rxn 2) b)  H(rxn 1) =  H(rxn 2) -  H(rxn 3) -  H(rxn 4) c)  H(rxn 1) =  H(rxn 2) + 1/2  H(rxn 3) + 1/2 d)  H(rxn 1) =  H(rxn 3) -  H(rxn 2) + e)  H(rxn 1) =  H(rxn 2) - 1/2 

 H(rxn 4)
H(rxn 4)
H(rxn 3) - 1/2  H(rxn 4)
(14) All of the following statements are true except a) the fourth major energy level has one set of f orbitals b) the 2p orbitals can have a maximum of 6 electrons c) there are 5 d orbitals in a set d) the s orbital is spherical in shape e) the n = 2 energy level has d orbitals
(15) How many orbitals have the following quantum numbers: n = 3, l = 2? a) 1 b) 3 c) 5 d) 7 e) 9
CHE 106 Fall Exam #2 5

(16) Which of the following statements is/are true?
I The product of wavelength and frequency of light is a constant.
II. As the energy increases, the frequency of the radiation decreases.
III. As the wavelength of light increases, the frequency increases. a) I b) II c) III d) I and III e) II and III
(17) Which quantum number distinguishes the different shapes of the orbitals? a) n b) l c) m l d) m s e) all of these
(18) The contribution for which de Broglie is remembered in modern science is a) his statement that an electron can exist in an atom in discrete energy levels. b) his statement that no electron can have identical values for all 4 quantum numbers. c) his statement that electrons occupy all the orbitals of a given sublevel singly before
paring begins. d) his proposal that particles of matter should be associated with wavelike behavior. e) his statement that elements show periodic repetition of properties.
(19) All the following statements are true except a) the n = 2 energy level has d orbitals b) the 2p orbital can have a maximum of 6 electrons c) the fourth major energy level has one set of f orbitals d) the s orbital has a spherical shape e) there are five d orbitals in a set
(20) The maximum number of electrons that can occupy the 5d orbitals is a) 5 b) 10 c) 14 d) 18 e) 25
CHE 106 Fall Exam #2 6

(21) A lithium flame emits a red spectral line at a wavelength of 671 nm. Calculate the energy
of one photon of this light. a) none of the answers below b) 2.96 x 10
-19
J c) 2.96 x 10 -16 J d) 4.45 x 10
-26
J e) 4.45 x 10
-40
J
(22) What is the de Broglie wavelength of a 145 gram baseball traveling at a speed of 30.0 m/s
(67.1 mph)? a) 0.681 x 10
-34
m b) 5.08 x 10
-36
m c) 5.08 x 10
-34
m d) 1.52 x 10
-34
m e) 1.52 x 10
-31
m
(23) According to the rules for quantum numbers, which one of the following sets of quantum
numbers would be permissible for an electron? a) n = 1, l = 0, m l
= 0, m s
= +1 b) n = 3, l = 2, m l
= -3, m s
= -1/2 c) n = 2, l = 1, m l
= -1, m s
= +1/2 d) n = 0, l = 1, m l
= 0, m s
= -1/2 e) n = 1, l = 1, m l
= 0, m s
= +1/2
CHE 106 Fall Exam #2 7

(24) Which of the following statements related to the Pauli Exclusion Principle is/are correct?
I. No two electrons in an atom can have the same three quantum numbers.
II. An orbital can hold at most two electrons and these must have opposite spins.
III. The electron configuration 1s
2
2s
2
2p
8
satisfies the Pauli Exclusion Principle. a) I b) II c) III d) I and II e) II and III
(25) Which of the following statements is/are correct?
I. The elements nitrogen, phosphorus, and silicon tend to have similar chemical
properties
II. More elements are metalloids than are metals or nonmetals.
III. The element in period 3, group 17 tends to form ions with a charge of -2. a) I and II b) II and III c) I and III d) I e) None are correct
(26) Which of he following atoms designated by electronic configurations has the highest
ionization energy? a) [Ne] 3s
2
3p
2 b) [Xe] 4f
14
5d
10
6s
2
6p
3 c) [Ar] 3d 10 4s 2 4p 3 d) [Kr] 4d
10
5s
2
5p
3 e) [Ne] 3s
2
3p
3
(27) Which of the following species is isoelectronic with Kr? a) Sr
2+ b) K + c) Xe d) S
2e) In 3+
CHE 106 Fall Exam #2 8

(28) All of the following species are isoelectronic except a) S 2b) Cl
c) Mg
2+ d) Ca 2+ e) Ar
(29) Which of the following statements about different elements are true?
I. As is a metalloid and Se is a nonmetal.
II. Cu is a transition element and Ge is a metalloid.
III. Both F and I are halogen. a) I b) II c) III d) I and I e) I, II, and III
(30) Which of the following atoms has the largest atomic radius? a) P b) Sr c) I d) Mg e) Kr
CHE 106 Fall Exam #2 9

You MUST SHOW ALL WORK to get credit for the “Extra Credit” problems.
(EC 1) Using the Bohr theory, calculate the wavelength of the photon emitted by a hydrogen
atom undergoing a transition from the n=3 to n=2 level.


 a) b) c) d) e)
8R
H
9
5R
H
36
8R
H
9h
5R
H
36h
36hc
5R
H


(EC 2)  H fus
for sulfur (S atoms) is 17.7 kJ/mol of S. How many grams of sulfur can be melted
by 22.5 kJ of energy? (Think and use FLM) a) 9.8 g b) 19.5 g c) 26.2 g d) 40.7 g e) 52.5 g
CHE 106 Fall Exam #2 10