MC_Chem1A_Sp08_LecExam3

Multiple Choice
Identify the choice that best completes the statement or answers the question.

____	1.	Hund's rule states that the most stable arrangement of electrons (for a ground state electron configuration)
a.	has a filled valence shell of electrons.	
b.	has two electrons per orbital, each with identical spins.	
c.	has ml values greater than or equal to zero.	
d.	has the maximum number of unpaired electrons, all with the same spin.	
e.	has two electrons per orbital, each with opposing spins.	

____	2.	In molecules, as bond order increases,
a.	both bond length and bond energy increase.	
b.	both bond length and bond energy decrease.	
c.	bond length increases and bond energy is unchanged.	
d.	bond length is unchanged and bond energy increases.	
e.	bond length decreases and bond energy increases.	

____	3.	Which of the following has/have the electron configuration [Ne]3s23p6?

i.	S2-	
ii.	Cl	
iii.	Ar	
iv.	K+	
v.	Ca2+	

a.	i only	
b.	iv and v	
c.	ii and iii	
d.	i, iii, iv, and v	
e.	All have the electron configuration [Ne]3s23p6	

____	4.	Which of the following statements correctly describe ionic compounds?

i.	They never contain covalent bonds	
ii.	They are formed when atoms share their valence electrons	
iii.	They are usually solids at room temperature	
iv.	They are generally gases at ice water temperature	

a.	iii only	
b.	i and ii	
c.	i and iii	
d.	i and iv	
e.	i, ii, and iii	

____	5.	How is the bond in an F2 molecule formed?
a.	Overlap of the half-filled 1s orbitals of two fluorine atoms	
b.	Overlap of the half-filled 1s orbital from one fluorine atom with the half-filled 2p orbital from a second fluorine atom	
c.	Overlap of the half-filled 2p orbitals of two fluorine atoms	
d.	Transfer of an electron from one fluorine atom to the other	
e.	Transfer of an electron from one fluorine atom to third atom, followed by an electron from a neutral fluorine atom being shared with the electron-deficient fluorine atom to form the bond	

____	6.	What is the trend in electronegativities among the main group elements in the periodic table?
a.	Increase left to right; decrease top to bottom	
b.	Increase left to right; increase top to bottom	
c.	Decrease left to right; decrease top to bottom	
d.	Decrease left to right; increase top to bottom	
e.	There is no periodic trend for electronegativities	

____	7.	Which element will act as the positive pole in each of the following bonds:

Element	Electronegativity	
O	3.5	
F	4.0	
Cl	3.0	

a.	F in O–F and O in O–Cl	
b.	O in O–F and O in O–Cl	
c.	F in O–F and Cl in O–Cl	
d.	O in O–F and Cl in O–Cl	
e.	O, F, and Cl are all highly electronegative so there can be no positive pole	

____	8.	Arrange the following bonds in order of increasing polarity.

Element	Electronegativity	
C	2.5	
P	2.1	
As	2.0	
S	2.5	
Se	2.4	

a.	C-P < C-As < C-S < C-Se	
b.	C-Se < C-P < C-As < C-S	
c.	C-S < C-As < C-P < C- Se	
d.	C-As < C-P < C-Se < C-S	
e.	C-S < C-Se < C-P < C-As	

____	9.	How many single, double, and triple bonds are in the following molecule?

	# single bonds	# double bonds	# triple bonds	

a.	5                                   1                                   1	
b.	7                                   1                                   1	
c.	8                                   1                                   1	
d.	9                                   1                                   1	
e.	10                                 1                                   0	

____	10.	If the volume of a confined gas is quadrupled while its temperature remains constant, what change will be observed?
a.	The pressure of the gas will decrease to 1/4 its original value.	
b.	The pressure of the gas will quadruple.	
c.	The density of the gas will decrease to 1/2 its original value.	
d.	The average velocity of the molecules will quadruple.	
e.	The average velocity of the molecules will double.	

____	11.	A balloon is filled with He gas to a volume of 3.22 L at 32 °C. The balloon is placed in liquid nitrogen until its temperature reaches -132 °C. Assuming the pressure remains constant, what is the volume of the cooled balloon?
a.	0.628 L	
b.	0.781 L	
c.	1.24 L	
d.	1.49 L	
e.	6.96 L	

____	12.	What volume of CO2 at 15 °C and 1.50 atm contains the same number of molecules as 0.410 L of O2 at 35 °C and 3.00 atm?
a.	0.192 L	
b.	0.219 L	
c.	0.767 L	
d.	0.820 L	
e.	1.14 L	

____	13.	What volume is occupied by 8.50 g C2H2 at STP (standard temperature and pressure)? (R = 0.08206 L·atm/mol·K)
a.	0.670 L	
b.	7.31 L	
c.	7.98 L	
d.	68.7 L	
e.	191 L	

____	14.	If 6.46 L of gaseous ethanol is burned in excess oxygen, what is the maximum volume of carbon dioxide produced? Assume that the temperature of the reactants and products is 425 °C and the pressure remains constant at 1.00 atm.

CH3CH2OH(g) + 3 O2(g) ® 2 CO2(g) + 3 H2O(g)

a.	6.46 L	
b.	3.23 L	
c.	12.9 L	
d.	19.4 L	
e.	32.3 L	

____	15.	Carbon monoxide gas diffuses through a barrier at a rate of 0.480 mL/minute. If an unknown gas diffuses through the same barrier at a rate of 0.277 mL/minute, what is the molar mass of the gas?
a.	9.33 g/mol	
b.	21.3 g/mol	
c.	36.9 g/mol	
d.	44.01 g/mol	
e.	84.1 g/mol	

____	16.	Which of the following statements are CORRECT?

1.	Substances that retain their magnetism after they are withdrawn from a magnetic field are called ferromagnetic.	
2.	A diamagnetic substance is slightly repelled by a magnetic field.	
3.	An atom with an even number of electrons is diamagnetic.	

a.	1 only	
b.	2 only	
c.	3 only	
d.	1 and 2	
e.	1, 2, and 3	

____	17.	How many electrons can be described by the following quantum numbers: n = 4, l = 3, ml = -2, ms = +1/2?
a.	0	
b.	1	
c.	2	
d.	3	
e.	6	

____	18.	Which of the following sets of quantum numbers is allowed?
a.	n = 2, l = 1, ml = 1, ms = -1/2	
b.	n = 3, l = 2, ml = 1, ms = +1	
c.	n = 3, l = 1, ml = -3, ms = -1/2	
d.	n = 4, l = 4, ml = -1, ms = +1/2	
e.	n = 5, l = 2, ml = +2, ms = -1	

____	19.	For which of the following atoms is the common ion paramagnetic?
a.	Al	
b.	Mg	
c.	Ni	
d.	F	
e.	H	

____	20.	What is the ground state electron configuration for Cr3+?
a.	[Ar]	
b.	[Ar]3d34s2	
c.	[Ar]3d44s1	
d.	[Ar]3d3	
e.	[Ar]3d74s2	

____	21.	Which of the following elements would have the greatest difference between the first and the second ionization energies?
a.	Mg	
b.	Al	
c.	K	
d.	Ca	
e.	Sr	

____	22.	Which of the following elements has the most negative electron affinity?
a.	Li	
b.	B	
c.	C	
d.	N	
e.	F	

____	23.	Which combination of atoms is most likely to produce a compound with ionic bonds?
a.	Al and F	
b.	P and H	
c.	C and O	
d.	Si and O	
e.	S and Br	

____	24.	Which of the following species will have a Lewis structure most like that of carbon disulfide, CS2?
a.	NO2-	
b.	SO2	
c.	H2S	
d.	SF2	
e.	SCN-	

____	25.	What intermolecular force or bond is primarily responsible for the solubility of H2S in water?
a.	ion-dipole force	
b.	dipole-dipole force	
c.	ionic bonding	
d.	covalent bonding	
e.	hydrogen bonding	

____	26.	Which of the following is a correct Lewis structure for N2O?

a.	1	
b.	2	
c.	3	
d.	4	
e.	5	

____	27.	Which of the following are resonance structures for the formate ion, HCO2-?

a.	1 and 2	
b.	2 and 3	
c.	3 and 4	
d.	1, 3, and 4	
e.	2, 3, and 4	

____	28.	What is the correct Lewis structure for IF3?

a.	1	
b.	2	
c.	3	
d.	4	
e.	5	

____	29.	Use VSEPR theory to predict the electron-pair geometry and the molecular geometry of iodine trichloride, ICl3.
a.	The e--pair geometry is trigonal-planar, the molecular geometry is trigonal-planar.	
b.	The e--pair geometry is tetrahedral, the molecular geometry is trigonal-pyramidal.	
c.	The e--pair geometry is tetrahedral, the molecular geometry is trigonal-planar.	
d.	The e--pair geometry is trigonal-bipyramidal, the molecular geometry is T-shaped.	
e.	The e--pair geometry is trigonal-bipyramidal, the molecular geometry is trigonal-planar.	

____	30.	As molecular solids, which of the following will exhibit dipole-dipole intermolecular forces: PH3, SO3, Br2, and SiCl4?
a.	PH3 only	
b.	PH3 and SO3	
c.	SO3 and SiCl4	
d.	Br2 and SiCl4	
e.	PH3, SO3, and SiCl4	

____	31.	Which one of the following molecules will have the lowest boiling point?
a.	CCl4	
b.	CHCl3	
c.	CH2Cl2	
d.	CH3Cl	
e.	CH4	

____	32.	Which intermolecular force or bond is responsible for the density of H2O(s) being less than that of H2O(l)?
a.	London dispersion forces	
b.	hydrogen bonding	
c.	ionic bonding	
d.	covalent bonding	
e.	dipole/induced dipole forces	

____	33.	Which 3+ ion has the ground state electron configuration [Kr]4d5?
a.	Ru	
b.	Fe	
c.	Ag	
d.	Tc	
e.	Nb	

____	34.	What is the maximum number of electrons that can occupy the n = 5 shell?
a.	5	
b.	10	
c.	14	
d.	25	
e.	50	

____	35.	Use Lewis structures to predict the bond order for a nitrogen-oxygen bond in the nitrite ion, NO2-.
a.	1/2	
b.	1	
c.	4/3	
d.	3/2	
e.	3	

____	36.	What volume of oxygen, measured at STP, can be produced by the decomposition of potassium chlorate if 10.0 g of the salt is completely decomposed according to the equation
2 KClO3 ® 2 KCl + 3 O2
a.	0.915 L	
b.	1.22 L	
c.	1.83 L	
d.	1.37 L	
e.	2.74 L	

____	37.	Which of the following has a tetrahedral electron pair geometry surrounding the central atom?

i.	PH3	
ii.	BH3	
iii.	BeH2	
iv.	OF2	

a.	i only	
b.	ii only	
c.	iv only	
d.	i and ii	
e.	i and iv	

____	38.	Which of the following has a trigonal planar electron pair geometry surrounding the central atom?

i.	NF3	
ii.	BF3	
iii.	PH3	
iv.	IO3-	

a.	i only	
b.	ii only	
c.	i, ii, and iii	
d.	i, ii, and iv	
e.	i, ii, iii, and iv	

MC_Chem1A_Sp08_LecExam3
Answer Section

MULTIPLE CHOICE

	1.	ANS:	D	PTS:	1	OBJ:	8.4 Atomic Electron Configurations

	2.	ANS:	E	PTS:	1	OBJ:	9.10 Bond Properties: Order | Length | and Energy

	3.	ANS:	D

	Feedback	
A	Incorrect. See Section 12.1, Goal 2.	
B	Incorrect. See Section 12.1, Goal 2.	
C	Incorrect. See Section 12.1, Goal 2.	
D	Correct.	
E	Incorrect. See Section 12.1, Goal 2.	

PTS:	1

	4.	ANS:	A

	Feedback	
A	Correct.	
B	Incorrect. See Section 12.2, Goal 3.	
C	Incorrect. See Section 12.2, Goal 3.	
D	Incorrect. See Section 12.2, Goal 3.	
E	Incorrect. See Section 12.2, Goal 3.	

PTS:	1

	5.	ANS:	C

	Feedback	
A	Incorrect. See Section 12.3, Goal 5.	
B	Incorrect. See Section 12.3, Goal 5.	
C	Correct.	
D	Incorrect. See Section 12.3, Goal 5.	
E	Incorrect. See Section 12.3, Goal 5.	

PTS:	1

	6.	ANS:	A

	Feedback	
A	Correct.	
B	Incorrect. See Section 12.4, Goal 7.	
C	Incorrect. See Section 12.4, Goal 7.	
D	Incorrect. See Section 12.4, Goal 7.	
E	Incorrect. See Section 12.4, Goal 7.	

PTS:	1

	7.	ANS:	D

	Feedback	
A	Incorrect. See Section 12.4, Goal 8.	
B	Incorrect. See Section 12.4, Goal 8.	
C	Incorrect. See Section 12.4, Goal 8.	
D	Correct.	
E	Incorrect. See Section 12.4, Goal 8.	

PTS:	1

	8.	ANS:	E

	Feedback	
A	Incorrect. See Section 12.4, Goal 9.	
B	Incorrect. See Section 12.4, Goal 9.	
C	Incorrect. See Section 12.4, Goal 9.	
D	Incorrect. See Section 12.4, Goal 9.	
E	Correct.	

PTS:	1

	9.	ANS:	B

	Feedback	
A	Incorrect. See Section 12.5, Goal 10.	
B	Correct.	
C	Incorrect. See Section 12.5, Goal 10.	
D	Incorrect. See Section 12.5, Goal 10.	
E	Incorrect. See Section 12.5, Goal 10.	

PTS:	1

	10.	ANS:	A	PTS:	1	OBJ:	12.2 Gas Laws: The Experimental Basis

	11.	ANS:	D	PTS:	1	OBJ:	12.2 Gas Laws: The Experimental Basis

	12.	ANS:	C	PTS:	1	OBJ:	12.2 Gas Laws: The Experimental Basis

	13.	ANS:	B	PTS:	1	OBJ:	12.3 The Ideal Gas Law

	14.	ANS:	C	PTS:	1	OBJ:	12.4 Gas Laws and Chemical Reactions

	15.	ANS:	E	PTS:	1	OBJ:	12.7 Effusion and Diffusion

	16.	ANS:	D	PTS:	1	OBJ:	8.1 Electron Spin	

	17.	ANS:	B	PTS:	1	OBJ:	8.2 The Pauli Exclusion Principle

	18.	ANS:	A	PTS:	1	OBJ:	8.2 The Pauli Exclusion Principle

	19.	ANS:	C	PTS:	1	OBJ:	8.5 Electron Configurations of Ions

	20.	ANS:	D	PTS:	1	OBJ:	8.5 Electron Configurations of Ions

	21.	ANS:	C	PTS:	1	OBJ:	8.6 Atomic Properties and Periodic Trends

	22.	ANS:	E	PTS:	1	OBJ:	8.6 Atomic Properties and Periodic Trends

	23.	ANS:	A	PTS:	1	OBJ:	9.2 Chemical Bond Formation

	24.	ANS:	E	PTS:	1	OBJ:	9.4 Covalent Bonding and Lewis Structures

	25.	ANS:	B	PTS:	1	OBJ:	13.2 Intermolecular Forces

	26.	ANS:	B	PTS:	1	OBJ:	9.4 Covalent Bonding and Lewis Structures

	27.	ANS:	C	PTS:	1	OBJ:	9.5 Resonance		

	28.	ANS:	B	PTS:	1	OBJ:	9.6 Exceptions to the Octet Rule

	29.	ANS:	D	PTS:	1	OBJ:	9.7 Molecular Shapes	

	30.	ANS:	A	PTS:	1	OBJ:	13.2 Intermolecular Forces

	31.	ANS:	E	PTS:	1	OBJ:	13.2 Intermolecular Forces

	32.	ANS:	B	PTS:	1	OBJ:	13.3 Hydrogen Bonding

	33.	ANS:	A	PTS:	1	OBJ:	8.5 Electron Configurations of Ions

	34.	ANS:	E	PTS:	1	OBJ:	8.2 The Pauli Exclusion Principle

	35.	ANS:	D	PTS:	1	OBJ:	9.10 Bond Properties: Order | Length | and Energy

	36.	ANS:	E

	Feedback	
A	Incorrect. See Section 14.6, Goal 7.	
B	Incorrect. See Section 14.6, Goal 7.	
C	Incorrect. See Section 14.6, Goal 7.	
D	Incorrect. See Section 14.6, Goal 7.	
E	Correct.	

PTS:	1

	37.	ANS:	E

	Feedback	
A	Incorrect. See Section 13.2, Goal 2.	
B	Incorrect. See Section 13.2, Goal 2.	
C	Incorrect. See Section 13.2, Goal 2.	
D	Incorrect. See Section 13.2, Goal 2.	
E	Correct.	

PTS:	1

	38.	ANS:	B

	Feedback	
A	Incorrect. See Section 13.2, Goal 2.	
B	Correct.	
C	Incorrect. See Section 13.2, Goal 2.	
D	Incorrect. See Section 13.2, Goal 2.	
E	Incorrect. See Section 13.2, Goal 2.	

PTS:	1