Chemistry Review CH 7-8

Please Note for Test Review - Use this plus the worksheet assignments to prepare for the Summative Assessment for these 2 chapters.

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

____	1.	Which of the following is NOT a property of an ionic compound?
a.	low boiling point	c.	hardness	
b.	brittleness	d.	molten compound conducts electricity	

____	2.	What is the metallic ion in the compound CuCl2?
a.	Cu2–	c.	Cu+	
b.	Cu–	d.	Cu2+	

____	3.	What is the formula for the compound formed by calcium ions, Ca2+, and chloride ions, Cl–?
a.	CaCl	c.	CaCl3	
b.	Ca2Cl	d.	CaCl2	

____	4.	The chemical formula for an ionic compound represents the
a.	number of atoms in each molecule.	
b.	number of ions in each molecule.	
c.	simplest ratio of ions that results in an electrically neutral compound.	
d.	total number of ions in the crystal lattice.	

____	5.	The chemical bond formed when two atoms share one or more pairs of electrons is a(n)
a.	ionic bond.	c.	polar bond.	
b.	orbital bond.	d.	covalent bond.	

____	6.	The correct Lewis structure for the oxygen atom has
a.	one pair of valence electrons and one single valence electron.	
b.	two pairs of valence electrons and one single valence electron.	
c.	two pairs of valence electrons and two single valence electrons.	
d.	three pairs of valence electrons.	

____	7.	In a double bond, two atoms share a total of _____ electrons.
a.	two	c.	four	
b.	three	d.	six	

____	8.	The correct Lewis structure for a molecule of the compound C2H2 contains
a.	three single bonds.	c.	three double bonds.	
b.	two double bonds.	d.	one triple bond.	

____	9.	Which of the following number of atoms can form a tetrahedral molecule?
a.	two	c.	four	
b.	three	d.	five	

____	10.	According to VSEPR theory, a molecule with the molecular formula of A2 is
a.	linear in shape.	c.	bent.	
b.	a dipole.	d.	Both (a) and (b)	

____	11.	According to VSEPR theory, the molecular shape of CO2 is classified as
a.	linear.	c.	trigonal planar.	
b.	bent.	d.	trigonal pyramidal.	

____	12.	According to VSEPR theory, the molecular shape of H2O is classified as
a.	linear.	c.	trigonal planar.	
b.	bent.	d.	trigonal pyramidal.	

____	13.	How many valence electrons are in an atom of phosphorus?
a.	2	c.	4	
b.	3	d.	5	

____	14.	What is the electron configuration of the calcium ion?
a.	1s2s2p3s3p	c.	1s2s2p3s3p4s	
b.	1s2s2p3s3p4s	d.	1s2s2p3s	

____	15.	What is the charge on the strontium ion?
a.	2–	c.	1	
b.	1–	d.	2	

____	16.	The octet rule states that, in chemical compounds, atoms tend to have ____.
a.	the electron configuration of a noble gas	
b.	more protons than electrons	
c.	eight electrons in their principal energy level	
d.	more electrons than protons	

____	17.	What is the formula of the ion formed when tin achieves a stable electron configuration?
a.	Sn	c.	Sn	
b.	Sn	d.	Sn	

____	18.	Which of the following particles are free to drift in metals?
a.	protons	c.	neutrons	
b.	electrons	d.	cations	

____	19.	Which is a typical characteristic of an ionic compound?
a.	Electron pairs are shared among atoms.	
b.	The ionic compound has a low solubility in water.	
c.	The ionic compound is described as a molecule.	
d.	The ionic compound has a high melting point.	

____	20.	Which of these elements does not exist as a diatomic molecule?
a.	Ne	c.	H	
b.	F	d.	I	

____	21.	Why do atoms share electrons in covalent bonds?
a.	to become ions and attract each other	
b.	to attain a noble-gas electron configuration	
c.	to become more polar	
d.	to increase their atomic numbers	

____	22.	Which of the following diatomic molecules is joined by a double covalent bond?
a.		c.		
b.		d.		

____	23.	According to VSEPR theory, molecules adjust their shapes to keep which of the following as far apart as possible?
a.	pairs of valence electrons	c.	mobile electrons	
b.	inner shell electrons	d.	the electrons closest to the nuclei	

Numeric Response

	24.	How many valence electrons are in bromine?

	25.	How many electrons does a gallium atom give up when it becomes an ion?

Completion
Complete each statement.

	26.	The tendency of atoms of elements to gain or lose electrons so that their outer s and p orbitals are filled with eight electrons is called the ____________________ rule.

	27.	In chemistry, any one of two or more possible configurations of the same compound that have identical geometry but different arrangements of electrons is called a(n) ____________________ structure.

Matching

Match each item with the correct statement below.
a.	metallic bond	d.	electron dot structure	
b.	octet rule	e.	valence electron	
c.	ionic bond	

____	28.	an electron in the highest occupied energy level of an atom

____	29.	Atoms react so as to acquire the stable electron structure of a noble gas.

____	30.	a depiction of valence electrons around the symbol of an element

____	31.	the force of attraction binding oppositely charged ions together

____	32.	the attraction of valence electrons for metal ions

Match each item with the correct statement below.
a.	hydrogen bond	c.	polar bond	
b.	double covalent bond	d.	single covalent bond	

____	33.	a covalent bond between two atoms of significantly different electronegativities

____	34.	a covalent bond in which only one pair of electrons is shared

____	35.	a covalent bond in which two pairs of electrons are shared

____	36.	a type of bond that is very important in determining the properties of water and of important biological molecules such as proteins and DNA

Match each item with the correct statement below.
a.	network solid	c.	VSEPR theory	
b.	dipole interaction	d.	bond dissociation energy	

____	37.	energy needed to break a single bond between two covalently bonded atoms

____	38.	crystal in which all the atoms are covalently bonded to each other

____	39.	shapes adjust so valence-electron pairs are as far apart as possible

____	40.	attraction between polar molecules

Short Answer

	41.	Rank the following substances in the most likely order of increasing bond energies.
Cl2: Cl–Cl bond length = 199 pm
HI: H–I bond length = 161 pm
HCl: H–Cl bond length = 127 pm
I2: I–I bond length = 266 pm

Problem

	42.	Draw a Lewis structure for the oxalate ion .

	43.	Draw a Lewis structure for the ammonium ion NH4+.

Essay

	44.	Can some atoms exceed the limits of the octet rule in bonding? If so, give an example.

Chemistry Review CH 7-8
Answer Section

MULTIPLE CHOICE

	1.	ANS:	A	PTS:	1	DIF:	I	OBJ:	5.2.2
STA:	2a

	2.	ANS:	D	PTS:	1	DIF:	II	OBJ:	5.3.1

	3.	ANS:	D	PTS:	1	DIF:	II	OBJ:	5.3.2

	4.	ANS:	C	PTS:	1	DIF:	II	OBJ:	5.3.2

	5.	ANS:	D	PTS:	1	DIF:	I	OBJ:	6.1.1
STA:	2a

	6.	ANS:	C	PTS:	1	DIF:	I	OBJ:	6.2.1
STA:	2e

	7.	ANS:	C	PTS:	1	DIF:	I	OBJ:	6.2.2
STA:	2e

	8.	ANS:	D	PTS:	1	DIF:	II	OBJ:	6.2.2
STA:	2e

	9.	ANS:	D	PTS:	1	DIF:	II	OBJ:	6.3.1
STA:	2f*

	10.	ANS:	A	PTS:	1	DIF:	II	OBJ:	6.3.1
STA:	2f*

	11.	ANS:	A	PTS:	1	DIF:	I	OBJ:	6.3.1
STA:	2f*

	12.	ANS:	B	PTS:	1	DIF:	I	OBJ:	6.3.1
STA:	2f*

	13.	ANS:	D	PTS:	1	DIF:	L1	REF:	p. 187
OBJ:	7.1.1  Determine the number of valence electrons in an atom of a representative element.
STA:	Ch.1.c | Ch.2.a | Ch.1.d

	14.	ANS:	A	PTS:	1	DIF:	L2	REF:	p. 188 | p. 189
OBJ:	7.1.1  Determine the number of valence electrons in an atom of a representative element.
STA:	Ch.1.g

	15.	ANS:	D	PTS:	1	DIF:	L1	REF:	p. 190
OBJ:	7.1.2  Explain how the octet rule applies to atoms of metallic and nonmetallic elements.
STA:	Ch.1.c | Ch.2.g		

	16.	ANS:	A	PTS:	1	DIF:	L2	REF:	p. 188
OBJ:	7.1.2  Explain how the octet rule applies to atoms of metallic and nonmetallic elements.
STA:	Ch.2.a

	17.	ANS:	A	PTS:	1	DIF:	L2	REF:	p. 190
OBJ:	7.1.3  Describe how cations form.	STA:	Ch.3.a

	18.	ANS:	B	PTS:	1	DIF:	L1	REF:	p. 201
OBJ:	7.3.1  Model the valence electrons of metal atoms.	STA:	Ch.2.a

	19.	ANS:	D	PTS:	1	DIF:	L2	REF:	p. 244
OBJ:	8.1.1  Distinguish between the melting points and boiling points of molecular compounds and ionic compounds.	STA:	Ch.2.a

	20.	ANS:	A	PTS:	1	DIF:	L1	REF:	p. 217
OBJ:	8.2.1  Describe how electrons are shared to form a covalent bonds and identify exceptions to the octet rule.	STA:	Ch.2.a

	21.	ANS:	B	PTS:	1	DIF:	L2	REF:	p. 217
OBJ:	8.2.1  Describe how electrons are shared to form a covalent bonds and identify exceptions to the octet rule.	STA:	Ch.2.a

	22.	ANS:	A	PTS:	1	DIF:	L2	REF:	p. 221
OBJ:	8.2.3  Describe how atoms form double or triple covalent bonds.	
STA:	Ch.2.a

	23.	ANS:	A	PTS:	1	DIF:	L1	REF:	p. 232
OBJ:	8.3.2  Describe how VSEPR theory helps predict the shapes of molecules.
STA:	Ch.2.a

NUMERIC RESPONSE

	24.	ANS:	7

PTS:	1	DIF:	L1	REF:	p. 188	
OBJ:	7.1.1  Determine the number of valence electrons in an atom of a representative element.
STA:	Ch.1.c | Ch.1.d		

	25.	ANS:	3

PTS:	1	DIF:	L2	REF:	p. 190	OBJ:	7.1.3  Describe how cations form.
STA:	Ch.2.a

COMPLETION

	26.	ANS:	octet

PTS:	1	DIF:	I	OBJ:	5.1.2	STA:	1d

	27.	ANS:	resonance

PTS:	1	DIF:	I	OBJ:	6.2.3

MATCHING

	28.	ANS:	E	PTS:	1	DIF:	L1	REF:	p. 187
OBJ:	7.1.1  Determine the number of valence electrons in an atom of a representative element.
STA:	Ch.2.a

	29.	ANS:	B	PTS:	1	DIF:	L1	REF:	p. 188
OBJ:	7.1.2  Explain how the octet rule applies to atoms of metallic and nonmetallic elements.
STA:	Ch.2.a

	30.	ANS:	D	PTS:	1	DIF:	L1	REF:	p. 188
OBJ:	7.1.4  Explain how anions form.	STA:	Ch.2.e

	31.	ANS:	C	PTS:	1	DIF:	L1	REF:	p. 192
OBJ:	7.1.4  Explain how anions form.

	32.	ANS:	A	PTS:	1	DIF:	L1	REF:	p. 194
OBJ:	7.2.1  Explain the electrical charge of an ionic compound.		
STA:	Ch.2.a

	33.	ANS:	C	PTS:	1	DIF:	L1	REF:	p. 218
OBJ:	8.1.2  Describe the information a molecular formula provides.	
STA:	Ch.2.a

	34.	ANS:	D	PTS:	1	DIF:	L1	REF:	p. 217
OBJ:	8.2.1  Describe how electrons are shared to form a covalent bonds and identify exceptions to the octet rule.	STA:	Ch.2.a

	35.	ANS:	B	PTS:	1	DIF:	L1	REF:	p. 221
OBJ:	8.2.1  Describe how electrons are shared to form a covalent bonds and identify exceptions to the octet rule.	STA:	Ch.2.a

	36.	ANS:	A	PTS:	1	DIF:	L1	REF:	p. 223
OBJ:	8.2.4  Distinguish between a covalent bond and a coordinate covalent bond and describe how the strength of a covalent bond is related to its bond dissociation energy.	
STA:	Ch.2.a

	37.	ANS:	D	PTS:	1	DIF:	L1	REF:	p. 226
OBJ:	8.2.5  Describe how oxygen atoms are bonded in ozone.	STA:	Ch.2.a

	38.	ANS:	A	PTS:	1	DIF:	L1	REF:	p. 230
OBJ:	8.3.1  Describe the relationship between atomic and molecular orbitals.
STA:	Ch.2.a

	39.	ANS:	C	PTS:	1	DIF:	L1	REF:	p. 230
OBJ:	8.3.1  Describe the relationship between atomic and molecular orbitals.
STA:	Ch.2.a

	40.	ANS:	B	PTS:	1	DIF:	L1	REF:	p. 232
OBJ:	8.3.2  Describe how VSEPR theory helps predict the shapes of molecules.
STA:	Ch.2.a

SHORT ANSWER

	41.	ANS:	
(in increasing bond energies) I2, Cl2, HI, and HCl

PTS:	1	DIF:	I	OBJ:	6.1.2

PROBLEM

	42.	ANS:	
2 C atoms with 4 electrons  2 ´ 4 = 8
4 O atoms with 6 electrons  4 ´ 6 = 24
8 + 24 = 32 valence electrons
2 – charge  2 extra electrons
32 + 2 = 34 electrons total

PTS:	1	DIF:	II	OBJ:	6.2.1	STA:	2e

	43.	ANS:	

PTS:	1	DIF:	II	OBJ:	6.2.1	STA:	2e

ESSAY

	44.	ANS:	
Yes, sulfur and phosphorus can expand the octet. They can have 12 or 10 valence electrons, respectively, when combined with small halogens. In PCl, phosphorus has 10 valence electrons.

PTS:	1	DIF:	L2	REF:	p. 228 | p. 229		
OBJ:	8.2.5  Describe how oxygen atoms are bonded in ozone.	STA:	Ch.2.a