Answer all questions
Section A
1.	How many neutrons are in an atom of gallium-71?
a.		71
b.		40
c.		111
d.		31
e.		102

2.	Silver has two stable isotopes with masses of 106.90509 u and 108.9047 u. The average molar mass of silver is 107.868 u. What is the percent abundance of each isotope?
a.	50.0% Ag-107 and 50.0% Ag-109
b.	51.8% Ag-107 and 48.2% Ag-109
c.	55.4% Ag-107 and 44.6% Ag-109
d.	48.2% Ag-107 and 51.8% Ag-109
e.	44.6% Ag-107 and 55.4% Ag-109

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3.	Which of the following elements is not a metalloid?
a.	boron
b.	selenium
c.	germanium
d.	arsenic
e.	silicon

4.	What is the correct formula for ammonium bromide?
a.	NH4Br
b.	(NH4)2Br
c.	NH3Br
d.	NH4Br2
e.	NH2Br

5.	What is the correct formula for cobalt(III) bromide?
a.	CoBr
b.	CoBr3
c.	Co2Br3
d.	Co3Br2
e.	Co3Br

6.	What is the molar mass of calcium chloride hexahydrate?
a.	75.53 g/mol
b.	111.0 g/mol
c.	117.0 g/mol
d.	183.6 g/mol
e.	219.1 g/mol

7.	Calculate the number of moles of aluminum oxide in 6.83 g Al2O3.
a.	6.70 x 10–2 mol
b.	6.96 x 102 mol
c.	0.253 mol
d.	0.127 mol
e.	1.56 x 10–3 mol

8.	How many bromide ions are in 0.55 g of iron(III) bromide?
a.	1.1 x 1021 ions
b.	3.4 x 1021 ions
c.	3.3 x 1023 ions
d.	9.9 x 1023 ions
e.	2.9 x 1026 ions

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9.	A 3.592 g sample of hydrated magnesium bromide, MgBr2⋅xH2O, is dried in an
oven. When the anhydrous salt is removed from the oven, its mass is 2.263 g. What is the value of x?
a.		1
b.		3
c.		6
d.		8
e.		12

	10.	An ionic compound has the formula MCl2. The mass of 0.3011 mol of the
compound is 62.69 grams. What is the identity of the metal?
a.	Ni
b.	Cu
c.	Sn
d.	Hg
e.	Ba

11.	According to the Bohr model for the hydrogen atom, the energy necessary to
excite an electron from n = 1 to n = 2 is ____ the energy necessary to excite an electron from n = 2 to n = 3.
a.	less than
b.	greater than
c.	equal to
d.	either equal to or greater than
e.	either less than or equal to

12.	Which element has the ground state electron configuration 1s22s22p63s23p3?
a.	V
b.	P
c.	Si
d.	Ti
e.	As
	13.	Which element has the following ground state electron configuration?
a.	In
b.	Y
c.	Nb
d.	Tl
e.	Ga

Page 4 of 12

14.	What is the correct orbital box diagram for the ground state electron configuration of Ni?
a.
b.
c.
d.
e.
	15.	Which of the following cations has the same number of unpaired electrons as
Fe2+?
a.	Ni2+
b.	Fe3+
c.	Cr2+
d.	Mn2+
e.	Co2+
Section B

16.	Metals react with oxygen gas to produce oxides with the general formula MxOy.
Write a balanced chemical equation for the reaction of aluminium with oxygen to yield aluminium(III) oxide.
a.	4 Al(s) + O2(g) → 2 Al2O(s)
b.	Al (s) + 2O2(g) → AlO2(s)
c.	2 Al (s) + O2(g) → 2 AlO(s)
d.	Al (s) + O(g) → Al O(s)
e.	4 Al (s) + 3O2(g) → 2 Al2O3(s)

17.	The products of the complete combustion of octane, C8H18, are carbon dioxide
and water. Write a balanced chemical equation for this reaction.
a.	C8H18( ) → 8 C(s) + 9 H2(g)
b.	C8H18( ) + 25 O2(g) → 8 CO2 (g) + 9 H2O(g)
c.	2 C8H18( ) + 25 O2(g) → 16 CO2(g) + 18 H2O(g)
d.	C8H18( ) + 16 O2(g) → 8 CO2(g) + 9 H2(g)
e.	2 C8H18( ) + 17 O2(g) → 16 CO(g) + 18 H2O(g)

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18.	The reaction of elemental chlorine with potassium iodide yields elemental iodine and potassium chloride. Write a balanced chemical equation for this reaction.
a.	Cl2(g) + KI(s) → I(s) + KCl2(s)
b.	Cl2(g) + 2 KI(s) → I2(s) + 2 KCl(s)
c.	Cl2(g) + KI2(s) → I2(s) + KCl2(s)
d.	Cl(g) + KI(s) → I(s) + KCl(s)
e.	Cl2(g) + 2 K2I(s) → I2(s) + 2 K2Cl(s)

19.	Which of the following compounds are soluble in water: NH4NO3, Fe2S3, CuCO3, and SrCl2?
a.	NH4NO3 only
b.	NH4NO3 and Fe2S3
c.	Fe2S3 and CuCO3
d.	CuCO3 and SrCl2
e.	NH4NO3 and SrCl2

20.	What is the net ionic equation for the reaction of aqueous sodium hydroxide and aqueous iron(II) chloride?
a.	Na+(aq) + OH–(aq) → NaOH(s)
b.	Na+(aq) + Cl–(aq) → NaCl(s)
c.	Fe2+(aq) + 2 OH–(aq) → Fe(OH)2(s)
d.	Fe2+(aq) + OH–(aq) → FeOH+(s)
e.	Fe2+(aq) + 2 Cl–(aq) → FeCl2(s)

21.	Which species in the reaction below undergoes reduction?
H2O(g) + CO(g) → H2(g) + CO2(g)
a.	H2O
b.	CO
c.	H2
d.	CO2
e.	None

22.	When strongly heated, boric acid breaks down to boric oxide and water. What
mass of boric oxide is formed from the decomposition of 15.0 g B(OH)3?
	2 B(OH)3(s) → B2O3(s) + 3 H2O(g)
a.		7.50 g
b.		15.0 g
c.		8.44 g
d.		16.9 g
e.		33.8 g


Page 6 of 12

23.	What mass of water is produced by the complete combustion of 2.68 grams of ethanol, C2H5OH?
a.		1.05 g
b.		1.17 g
c.		3.14 g
d.		0.439 g
e.		20.6 g

24.	If 15.0 g N2 and 2.00 g H2 react to produce 1.38 g NH3, what is the percent yield
of the reaction?
	N2(g) + 3 H2(g) → 2 NH3(g)
a.		7.57%
b.		12.2%
c.		8.12%
d.		15.1%
e.		8.17%


25.	An unknown hydrocarbon contains carbon, hydrogen, and oxygen. Combustion
of 1.5000 g of the hydrocarbon produces 1.1738 g H2O and 2.1505 g CO2. What is the empirical formula of the hydrocarbon?
a.	CHO
b.	C2H3O
c.	C3H4O
d.	C3H8O3
e.	C5H5O

26.	The pH of a vinegar solution is 4.15. What is the H3O+ concentration of the solution?
a.		7.1 × 10–5 M
b.		1.6 × 10–2 M
c.		0.62 M
d.		1.4 M
e.		1.4 × 104 M

27.	A mass of 0.4113 g of an unknown acid, HA, is titrated with NaOH. If the acid
reacts with 28.10 mL of 0.1055 M NaOH(aq), what is the molar mass of the acid?
a.	2.965 × 10–3 g/mol
b.	9.128 g/mol
c.	138.7 g/mol
d.	337.3 g/mol
e.	820.7 g/mol

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	28.	If 495 J is required to change the temperature of 12.7 g of sodium chloride from
275.0 K to 335.0 K, what is the specific heat capacity of sodium chloride?
a.	0.866 J/g•K
b.	2.60 J/g•K
c.	0.650 J/g•K
d.	1.15 J/g•K
e.	2.83 x 105 J/g•K


29.	The thermochemical equation for the combustion of butane is shown below.
C4H10(g) + 13/2 O2(g) ~ 4 CO2(g) + 5 H2O( )	4rH° = –2877 kJ/mol-rxn
What is the enthalpy change for the following reaction?
8 CO2(g) + 10 H2O( ) ~ 2 C4H10(g) + 13 O2(g)
a.	+1439 kJ/mol-rxn
b.	+2877 kJ/mol-rxn
c.	–5754 kJ/mol-rxn
d.	–2877 kJ/mol-rxn
e.	+5754 kJ/mol-rxn

30.	Hydrazine, N2H4, is a liquid used as a rocket fuel. It reacts with oxygen to yield
nitrogen gas and water.
N2H4( ) + O2(g) ~ N2(g) + 2 H2O( )
The reaction of 6.50 g N2H4 evolves 126.2 kJ of heat. Calculate the enthalpy
change per mole of hydrazine combusted.
a.	–19.4 kJ/mol
b.	–25.6 kJ/mol
c.	–126 kJ/mol
d.	–622 kJ/mol
e.	–820. kJ/mol

Section C

31.	Which combination of atoms is most likely to produce a compound with
covalent bonds?
a.	K and Br
b.	Al and S
c.	S and Cl
d.	Sn and F
e.	Li and I

Page 8 of 12

32.	Which of the following statements is/are CORRECT?

1.	Ionic bonds form when one or more valence electrons are transferred from one atom to another.
2.	Covalent bonds involve sharing of electrons between atoms.
3.	In most covalently bonded compounds, electrons are NOT shared equally between the atoms.

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

33.	Which of the following statements is/are CORRECT?

1.	Chemical reactions result in the gain, loss, or rearrangement of valence electrons.
2.	For main group elements, the number of valence electrons equals eight minus the element’s group number.
3.	Core electrons are not involved in bonding or in chemical reactions.

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

34.	How many lone pairs of electrons are assigned to the carbon atom in carbon dioxide?
a.	0
b.	1
c.	2
d.	3
e.	4

35.	How many lone pairs of electrons are assigned to the nitrogen atom in NCl3?
a.	0
b.	1
c.	2
d.	3
e.	4

36.	How many lone pair of electrons are assigned to the fluorine atom in HF?
a.	0
b.	1
c.	2
d.	3
e.	4

Page 9 of 12

37.	draw the correct Lewis structure for PH3?



38.	The central atom in SCl2 is surrounded by
a.	two single bonds and no lone pairs of electrons.
b.	two single bonds and one lone pair of electrons.
c.	two single bonds and two lone pairs of electrons.
d.	one single bond, one double bond, and no lone pairs of electrons.
e.	one single bond, one double bond, and one lone pair of electrons.

39.	One resonance structure for OCN– ion is drawn below. What is the formal charge on each atom?
a.	O atom = 0, C atom = 0, and N atom = 0
b.	O atom = 0, C atom = 0, and N atom = –1
c.	O atom = –1, C atom = 0, and N atom = 0
d.	O atom = –1, C atom = –1, and N atom = +1
e.	O atom = +1, C atom = 0, and N atom = –2

40.	Which of the following are resonance structures for 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