SJCC_Chem15_Sp07_LecExam1

Read questions carefully before answering .
Identify the choice from multiple choice questions that best completes the statement or answers the question.And then answer your choice on scantron.

____	1.	Which of the following changes is/are classified as chemical?

i.	dissolving vinegar in water	
ii.	evaporation of rubbing alcohol	
iii.	crushing rock	
iv.	fermenting apple juice	
v.	softening a glass tube by heating it	

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

____	2.	Which of the following correctly describes a homogeneous sample?
a.	Uniform appearance and composition throughout	
b.	Visibly different parts or phases	
c.	A mixture of diamond and graphite, which are both forms of carbon	
d.	Reacts with all elements	
e.	Reacts with all natural elements	

____	3.	Which of the following statements is false?
a.	Both elements and compounds are pure substances	
b.	The properties of a compound vary	
c.	An element cannot be decomposed chemically into other pure substances	
d.	A compound can be separated into other substances by chemical means	
e.	All of the above are true; none is false	

____	4.	Which of the following are elements?

i.	KOH	
ii.	Ne	
iii.	CO	
iv.	carbon tetrachloride	
v.	calcium	

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

____	5.	Identify the product(s) that is/are (a) compound(s) in the equation Zn + CoCl2 ® ZnCl2 + Co.
a.	CoCl2	
b.	ZnCl2	
c.	CoCl2 and ZnCl2	
d.	ZnCl2 and Co	
e.	Zn and CoCl2	

____	6.	When room temperature solutions of vinegar and drain cleaner are combined, the temperature of the resulting solution is greater than room temperature. Which of the following is the best explanation for this apparent violation of the Law of Conservation of Energy?
a.	Some of the mass of the room temperature solutions is converted into heat energy	
b.	The total energy of the original solutions is equal to the total energy of the resulting solution plus the heat energy	
c.	An ordinary chemical reaction occurs, so the Law of Conservation of Energy does not apply	
d.	The thermometer used to measure the temperature of the solutions must be faulty	
e.	The Law of Conservation of Energy does not apply to heat energy	

____	7.	What will be the cost in dollars for photocopies if you have 32 pages in a booklet, you need 175 booklets, and copies are 4.5 cents each?
a.	$12.44	
b.	$24.61	
c.	$39.68	
d.	$252	
e.	$25,200	

____	8.	Which of the following quantities is/are expressed in three significant figures?

i.	8.970 ´ 102 tons	
ii.	0.012 mL	
iii.	0.005 g	
iv.	5.1200 ft3	

a.	All are expressed in three significant figures	
b.	None is expressed in three significant figures	
c.	i and iv	
d.	ii and iii	
e.	iv only	

____	9.	One inch is defined as 2.54 cm. How many feet are in 1559 cm? Express the answer in the proper number of significant figures.
a.	5 ´ 101 ft	
b.	51 ft	
c.	51.1 ft	
d.	51.15 ft	
e.	51.148 ft	

____	10.	Find the mass of 35.7 mL of benzene if its density is 0.877 g/mL.
a.	2.46 ´ 10-2 g	
b.	3.19 ´ 10-2 g	
c.	40.7 g	
d.	35.7 g	
e.	31.3 g	

____	11.	Which of the following statements is false?
a.	The proton and the neutron are primarily responsible for the mass of an atom	
b.	The charge on electrons and protons are equal in magnitude but opposite in sign	
c.	The mass of a proton and a neutron are approximately the same	
d.	The mass of a proton is approximately one gram	
e.	A neutron, as its name suggests, is electrically neutral	

____	12.	Which of the three major subatomic particles has/have a mass of approximately one amu?

i.	electron	
ii.	proton	
iii.	neutron	

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

____	13.	Which of the following statements is false?
a.	Atoms of the same element that have different masses are called isotopes	
b.	The masses of isotopes vary because they have different numbers of electrons	
c.	The mass number of an isotope is the total number of protons and neutrons in the nucleus	
d.	You can find the mass number of an atom given the number of protons and neutrons, but without being given the number of electrons	
e.	Every atom of a particular element has the same number of protons	

____	14.	The nuclear symbol of an isotope of beryllium is . Indicate the number of protons, number of neutrons, atomic number, and mass number of the isotope.

	Number
of protons	Number
of neutrons	Atomic
number	Mass
number	

a.	6                        4                       10                      6	
b.	6                        4                       10                      4	
c.	4                        6                       4                        10	
d.	10                      4                       6                        4	
e.	4                        10                     4                        6	

____	15.	Which of the following is the best explanation of why the mass of an atom is usually expressed in atomic mass units rather than grams?
a.	An atomic mass unit is only used for carbon-12	
b.	The mass of one milliliter of water is one gram	
c.	The mass in grams is not known for atoms	
d.	The mass of an atom in grams is inconveniently small	
e.	Metric units such as grams are not applicable to atoms	

____	16.	Two natural isotopes exist for silver. 51.83% of the atoms have a mass of 106.90509 amu, and the remainder have a mass of 108.9047 amu. Calculate the atomic mass of silver.
a.	52.46 amu	
b.	55.41 amu	
c.	106.90509 amu	
d.	107.87 amu	
e.	108.9047 amu	

____	17.	Which of the following statements is/are false?

i.	Groups are arranged vertically in the periodic table	
ii.	Periods are arranged horizontally in the periodic table	
iii.	Periods are numbered from top to bottom	
iv.	There are eight elements in the first period of the periodic table	

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

____	18.	Which of the following is correct?
a.	The element H is in both the first period and the seventh period	
b.	The element Na is in Group 2A/2	
c.	The element Ge is in the fourth period and Group 4A/14	
d.	The element Cr is in the third period and Group 6B/6	
e.	More than one of the statements above are correct	

____	19.	Which of the following is correct for the element with Z = 9?

	Symbol	Atomic mass	Period	Group	

a.	F                        19.00                  2                        7A/17	
b.	F                        19.00                  7A/17                2	
c.	F                        9                         2                        7A/17	
d.	F                        9                         7A/17                2	
e.	Be                      9                         2                        2A/2	

____	20.	Which of the following symbol/name pairs is/are correctly matched?

i.	Fl, Fluorine	
ii.	N, Neon	
iii.	S, Sodium	
iv.	Ch, Chlorine	
v.	H, Hydrogen	

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

____	21.	Which of the following is a combination of two elemental symbols?
a.	ZN	
b.	AL	
c.	CO	
d.	NE	
e.	BR	

____	22.	For each of the following names, identify the elements that form stable diatomic molecules:

i.	nitrogen	
ii.	sulfur	
iii.	lithium	
iv.	bromine	
v.	oxygen	

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

____	23.	What are the formulas of the compounds magnesium sulfate and lithium bromite?
a.	Mg3(SO3)2, LiBr	
b.	MgSO3, LiBrO3	
c.	MgSO3, Li2BrO3	
d.	MgSO4, LiBrO2	
e.	MgSO4, Li2BrO3	

____	24.	What are the formulas of the compounds aluminum sulfide and ammonium chlorate?
a.	AlS, NH3ClO4	
b.	Al3S2, NH3ClO3	
c.	Al2S3, NH4ClO4	
d.	Al2S3, (NH4)2ClO3	
e.	Al2S3, NH4ClO3	

____	25.	For each of the following names, choose the correct formula:

i.	carbon disulfide	
ii.	dinitrogen pentoxide	
iii.	boron trifluoride	
iv.	silicon tetrabromide	
v.	disulfur dichloride	

	i            ii            iii            iv           v	

a.	CS2         Ni2O5     BF3        SiBr4       S2Cl2	
b.	CS2         N2O5      BF3        SiBr4       S2Cl2	
c.	CaS2       N2O5      BF3        SiBr4       S2Cl2	
d.	CS2         N2O5      BoF3      SiBr7       SCl2	
e.	CS2         N2O5      BFl3       SiBr9       SCh	

____	26.	For each of the following names, choose the correct formula.

i.	mercury(II) ion	
ii.	nitride ion	
iii.	zinc ion	

	i             ii              iii	

a.	Hg2+        N3-           Zn2+	
b.	Hg22+       N3-           Zn2+	
c.	Hg2+        N3-           Zn+	
d.	Hg22+       N23-          Zn+	
e.	Hg2+        N23-          Zn+	

____	27.	For each of the following formulas, choose the correct name.

i.	Pb2+	
ii.	S2-	
iii.	Ni2+	

	i                         ii                       iii	

a.	lead ion             sulfur ion           nickel ion	
b.	lead ion             sulfur ion           nickel(II) ion	
c.	lead(II) ion        sulfur ion           nickel ion	
d.	lead(II) ion        sulfide ion         nickel(II) ion	
e.	lead(II) ion        sulfide ion         nickel ion	

____	28.	Which of the following name-formula pairs is/are incorrect?

i.	bromous acid, HBrO2	
ii.	nitrate ion, NO3-	
iii.	periodate ion, IO3-	
iv.	hydrofluoric acid, HFl	
v.	telluric acid, H2TeO3 (tellurium, Z = 52)	

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

____	29.	Which of the following name-formula pairs is/are correct?

i.	HSeO3-, hydrogen selenite ion (Z = 34)	
ii.	HSO4-, hydrogen sulfite ion	
iii.	H2PO4-, bihydrogen phosphate ion	
iv.	HCO3-, hydrogen carbonate ion	

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

____	30.	List the number of atoms of each element in a formula unit of ammonium sulfate.
a.	1 nitrogen atom, 4 hydrogen atoms, 1 sulfur atom, 4 oxygen atoms	
b.	1 nitrogen atom, 3 hydrogen atoms, 1 sulfur atom, 4 oxygen atoms	
c.	2 nitrogen atoms, 6 hydrogen atoms, 1 sulfur atom, 4 oxygen atoms	
d.	2 nitrogen atoms, 8 hydrogen atoms, 1 sulfur atom, 4 oxygen atoms	
e.	1 nitrogen atom, 4 hydrogen atoms, 2 sulfur atoms, 8 oxygen atoms	

____	31.	Calculate the molecular mass of butane, C4H10.
a.	124.1 amu	
b.	58.1 amu	
c.	34.0 amu	
d.	14.0 amu	
e.	13.0 amu	

____	32.	How many atoms are in 0.188 mol Na?
a.	3.12 ´ 10-25	
b.	8.84 ´ 10-24	
c.	1.13 ´ 1023	
d.	6.02 ´ 1023	
e.	3.20 ´ 1024	

____	33.	What is the mass of 0.0490 mole of potassium sulfate?
a.	0.0490 g	
b.	3.55 kg	
c.	6.62 g	
d.	8.54 g	
e.	174.3 g	

____	34.	From the following, pick those that are not empirical formulas.

i.	C2H8	
ii.	C2H3	
iii.	C6H6	
iv.	C7H6	
v.	C7H21	

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

____	35.	What is the empirical formula of a compound that contains 80.0% carbon and 20.0% hydrogen by mass?
a.	CH3	
b.	CH2	
c.	CH	
d.	C3H	
e.	C2H3	

SJCC_Chem15_Sp07_LecExam1
Answer Section

MULTIPLE CHOICE

	1.	ANS:	B	PTS:	1

	2.	ANS:	A	PTS:	1

	3.	ANS:	B	PTS:	1

	4.	ANS:	D	PTS:	1

	5.	ANS:	B	PTS:	1

	6.	ANS:	B	PTS:	1

	7.	ANS:	D	PTS:	1

	8.	ANS:	B	PTS:	1

	9.	ANS:	D	PTS:	1

	10.	ANS:	E	PTS:	1

	11.	ANS:	D	PTS:	1

	12.	ANS:	E	PTS:	1

	13.	ANS:	B	PTS:	1

	14.	ANS:	C	PTS:	1

	15.	ANS:	D	PTS:	1

	16.	ANS:	D	PTS:	1

	17.	ANS:	D	PTS:	1

	18.	ANS:	C	PTS:	1

	19.	ANS:	A	PTS:	1

	20.	ANS:	E	PTS:	1

	21.	ANS:	C	PTS:	1

	22.	ANS:	C	PTS:	1

	23.	ANS:	D	PTS:	1

	24.	ANS:	E	PTS:	1

	25.	ANS:	B	PTS:	1

	26.	ANS:	A	PTS:	1

	27.	ANS:	E	PTS:	1

	28.	ANS:	E	PTS:	1

	29.	ANS:	E	PTS:	1

	30.	ANS:	D	PTS:	1

	31.	ANS:	B	PTS:	1

	32.	ANS:	C	PTS:	1

	33.	ANS:	D	PTS:	1

	34.	ANS:	D	PTS:	1

	35.	ANS:	A	PTS:	1