Chemistry Chapter 8 Final Exam Flashcards

Which of the following does not have eight valence electrons?

Cl-

Xe

Ti+4

Rb+

Sr+

How many hydrogen atoms must bond to silicon to give it an octet of valence electrons?

1

2

3

4

5

How many equivalent resonance forms can be drawn for SO2 without expanding octet on the sulfur atom? (Sulfur is the central atom.)

0

2

3

4

1

consider the BEST Lewis structures of the following oxyanions:

(i) NO2- (ii) NO3- (iii) SO32- (iv) SO42- (v) BrO3-

In which of the ions do all X-O bonds (X indicates the central atom) have the same length?

none

all

(i) and (ii)

(iii) and (v)

(iii), (iv), and (v)

Electropositivity ________ from left to right within a period and ________ from top to bottom within a group.

decreases, increases

increases, increases

increases, decreases

stays the same, increases

increases, stays the same

The ion PO43- has ________ valence electrons.

14

24

27

29

32

Of the possible bonds between carbon atoms (single, double, and triple), ________.

a triple bond is longer than a single bond

a double bond is stronger than a triple bond

a single bond is stronger than a triple bond

a double bond is longer than a triple bond

a single bond is stronger than a double bond

Using the table of average bond energies below, the △H for the reaction is ________ kJ.

C≡O (g) + 2H2 (g) → H3C-O-H (g)

Bond: C-O C=O C≡O C-H H-H O-H

ΔH (kJ/mol): 358 799 1072 413 436 463

+276

-276

+735

-735

-116

The oxidation number of phosphorus in PF5 is ________.

5

3

1

-5

0

Which of the following would have to lose three electrons in order to achieve a noble gas electron configuration?

Si Mg Al Cl P

Si, P

Al

P

Cl

Mg, Al, P

What is the electron configuration for the Fe3+ ion?

[Ar]4s13d6

[Ar]4s03d7

[Ar]4s03d5

[Ar]4s23d9

[Ne]3s23p10

The formula of palladium (IV) sulfide is ________.

Pd2S4

PdS4

Pd4S

PdS2

Pd2S2

The oxidation number of phosphorus in PF5 is ________.

5

3

1

-5

0

Resonance structures differ by ________.

number and placement of electrons

number of electrons only

placement of atoms only

number of atoms only

placement of electrons only

Determining lattice energy from Born-Haber cycle data requires the use of ________.

the octet rule

Coulomb's law

Periodic law

Hess's law

Avogadro's number

In the Lewis structure of ClF, the formal charge on Cl is ________, and the formal charge on F is ________.

Answers:

-1, -1

0, 0

0, -1

+1, -1

-1, +1

There are ________ valence electrons in the Lewis structure of CH3OCH3

20

16

18

24

22

There are ________ valence electrons in the Lewis structure of CH3Cl.

14

16

18

20

22

For a given arrangement of ions, the lattice energy increases as ionic radius ________ and as ionic charge ________.

decreases, increases

increases, decreases

increases, increases

decreases, decreases

This cannot be predicted.

The electron configuration of the S2- ion is ________.

[Ar]3s23p6

[Ar]3s23p2

[Ne]3s23p2

[Ne]3s23p6

[Kr]3s22p6

A valid Lewis structure of ________ cannot be drawn without violating the octet rule.

PO43-

SiF4

CF4

SeF4

NF3

There are ________ unpaired electrons in the Lewis symbol for an oxygen atom

0

1

2

4

3

The ion ICl4- has ________ valence electrons.

34

35

36

28

8

A valid Lewis structure of ________ cannot be drawn without violating the octet rule.

NF3

IF3

PF3

SbF3

NH3

What is the electron configuration for the Co2+ ion?

[Ar]4s13d6

[Ar]3d7

[Ar]3d5

[Ar]4s23d9

[Ne]3s23p10

The bond length in an HI molecule is 1.61 Å and the measured dipole moment is 0.44 D. What is the magnitude (in units of e) of the negative charge on I in HI?

(1 debye = 3.34 × 10-30 coulomb-meters; e = 1.6 × 10-19 coulombs)

1.6 × 10-19

0.057

9.1

1

0.22

The oxide of which of the following metals should have the greatest lattice energy?

calcium

strontium

magnesium

beryllium

barium

How many equivalent resonance forms can be drawn for CO32-? (Carbon is the central atom.)

1

2

3

4

0

Given the electronegativities below, which covalent single bond is most polar?

Element: H C N O

Electronegativity: 2.1 2.5 3.0 3.5

C—H

N—H

O—H

O—C

O—N

What species has the electron configuration [Ar]3d2?

Mn2+

Cr2+

V3+

Fe3+

K+

The electron configuration of the S2- ion is ________.

[Ar]3s23p6

[Ar]3s23p2

[Ne]3s23p2

[Ne]3s23p6

[Kr]3s22p6

The ________ ion has a noble gas electron configuration.

Be2+

Li2+

LiMg2-

Al2+

n the resonance form of ozone shown below, the formal charge on the central oxygen atom is ________.

+1

-1

+2

-2

What is the electron configuration for the Fe2+ ion?

[Ar]4s03d6

[Ar]4s23d4

[Ar]4s03d8

[Ar]4s23d8

[Ar]4s63d2

Which of the following does not have eight valence electrons?

Ca+

Rb+

Xe

Br-

All of the above have eight valence electrons.

Based on the octet rule, boron will most likely form a ________ ion.

B3-

B+

B3+

B2+

B2

What is the electron configuration for the Co2+ ion?

[Ar]4s13d6

[Ar]3d7

[Ar]3d5

[Ar]4s23d9

[Ne]3s23p10

The central atom in ________ does not violate the octet rule.

SF4

KrF2

CF4

XeF4

ICl4-

Given the electronegativities below, which covalent single bond is most polar?

Element: H C N O

Electronegativity: 2.1 2.5 3.0 3.5

C—H

N—H

O—H

O—C

O—N

Which of the following does not have eight valence electrons?

Ca+

Rb+

Xe

Br-

All of the above have eight valence electrons.

here are ______ covalent bonds in the Lewis Structure of CH3CHCl2.

7

6

8

5

4

How many single covalent bonds must a chlorine atom form to have a complete octet in its valence shell?

0

1

2

3

4

Using the table of bond dissociation energies, the ΔH for the following reaction is ________ kJ.

2HCl (g) + F2 (g) → 2HF (g) + Cl2 (g)

Bonds:

H-Cl 431

F-F 155

H-F 567

Cl-Cl 242

Answers:

-359

-223

359

223

208

The Lewis structure of N2H2 shows ________.

a nitrogen-nitrogen triple bond

a nitrogen-nitrogen single bond

each nitrogen has one nonbonding electron pair

each nitrogen has two nonbonding electron pairs

each hydrogen has one nonbonding electron pair

The electron configuration of the S2- ion is ________.

[Ar]3s23p6

[Ar]3s23p2

[Ne]3s23p2

[Ne]3s23p6

[Kr]3s22p6

Which two bonds are most similar in polarity?

O-F and Cl-F

B-F and Cl-F

Al-Cl and I-Br

I-Br and Si-Cl

C-Cl and Be-Cl

What is the maximum number of double bonds that a hydrogen atom can form?

0

1

2

3

4

The formal charge on nitrogen in NO3- is ________, where the Lewis structure of the ion is:

-1

0

+1

+2

-2

What species has the electron configuration [Ar]3d4?

Mn2+

Cr2+

V3+

Fe3+

K+

In ionic bond formation, the lattice energy of ions ________ as the magnitude of the ion charges _______ and the radii ________.

increases, decrease, increase

increases, increase, increase

decreases, increase, increase

increases, increase, decrease

increases, decrease, decrease

Elements from opposite sides of the periodic table tend to form ________.

covalent compound

ionic compounds

compounds that are gaseous at room temperature

homonuclear diatomic compounds

covalent compounds that are gaseous at room temperature

As the number of covalent bonds between two atoms increases, the distance between the atoms ________ and the strength of the bond between them ________.

increases, increases

decreases, decreases

increases, decreases

decreases, increases

is unpredictable

Of the bonds C-C, C=C, and C≡C, the C-C bond is ________.

strongest/shortest

strongest/longest

weakest/longest

weakest/shortest

intermediate in both strength and length

The ion ICl4- has ________ valence electrons.

34

35

36

28

8

The Lewis structure of HCN (H bonded to C) shows that ________ has ________ nonbonding electron pair(s)

C, 1

N, 1

H, 1

N, 2

C, 2

Electronegativity ________ from left to right within a period and ________ from top to bottom within a group.

decreases, increases

increases, increases

increases, decreases

stays the same, increases

increases, stays the same

Of the molecules below, the bond in ________ is the most polar.

HBr

HI

HCl

HF

H2

Which two bonds are most similar in polarity?

O-F and Cl-F

B-F and Cl-F

Al-Cl and I-Br

I-Br and Si-Cl

C-Cl and Be-Cl

Which of the following has eight valence electrons?

Ti4+

Kr

Cl-

Na+

all of the above

The halogens, alkali metals, and alkaline earth metals have ________ valence electrons, respectively.

7, 4, and 6

1, 5, and 7

8, 2, and 3

7, 1, and 2

2, 7, and 4

A ________ covalent bond between the same two atoms is the longest.

single

double

triple

strong

They are all the same length.

What is the electron configuration for the Fe2+ ion?

[Ar]4s03d6

[Ar]4s23d4

[Ar]4s03d8

[Ar]4s23d8

[Ar]4s63d2

Of the atoms below, ________ is the most electronegative.

Ba

Sr

Ca

Mg

Be

Of the possible bonds between carbon atoms (single, double, and triple), ________.

a triple bond is longer than a single bond

a double bond is stronger than a triple bond

a single bond is stronger than a triple bond

a double bond is longer than a triple bond

a single bond is stronger than a double bond

How many equivalent resonance structures can be drawn for the molecule of SO3 without having to violate the octet rule on the sulfur atom?

5

2

1

4

3

A valid Lewis structure of ________ cannot be drawn without violating the octet rule.

NI3

SO2

ICl5

SiF4

CO2

Based on the octet rule, iodine most likely forms an ________ ion.

I2+

I4+

I4-

I+

I-

A valid Lewis structure of ________ cannot be drawn without violating the octet rule.

NF3

IF3

PF3

SbF3

NH3

Of the bonds C-N, C=N, and C≡N, the C-N bond is ________.

strongest/shortest

strongest/longest

weakest/shortest

weakest/longest

intermediate in both strength and length

n the Lewis symbol for a nitrogen atom, there are ________ paired and ________ unpaired electrons.

two, three

one, three

three, two

zero, five

two, two

Using the table of average bond energies below, the ΔH for the reaction is ________ kJ.

Bond: C≡C C-C H-I C-I C-H

ΔH (kJ/mol): 839 348 299 240 413

Answers:

+160

-160

-217

-63

+63

The ________ ion has eight valence electrons.

Sc3+

Ti3+

V3+

Cr3+

Mn3+

How many hydrogen atoms must bond to silicon to give it an octet of valence electrons?

1

2

3

4

5

Using the table of average bond energies below, the △H for the reaction is ________ kJ.

C≡O (g) + 2H2 (g) → H3C-O-H (g)

Bond: C-O C=O C≡O C-H H-H O-H

ΔH (kJ/mol): 358 799 1072 413 436 463

Selected

Answers:

+276

-276

+735

-735

-116

The only noble gas without eight valence electrons is ________.

Ar

Ne

He

Kr

All noble gases have eight valence electrons.

How many equivalent resonance forms can be drawn for SO2 without expanding octet on the sulfur atom? (Sulfur is the central atom.)

0

2

3

4

1

The Lewis structure of AsH3 shows ________ nonbonding electron pair(s) on As.

0

1

2

3

This cannot be determined from the data given.

What is the maximum number of triple bonds that a carbon atom can form?

4

1

0

2

3

As the number of covalent bonds between two atoms increases, the distance between the atoms ________ and the strength of the bond between them ________.

increases, increases

decreases, decreases

increases, decreases

decreases, increases

is unpredictable

Lattice energy is ________.

the energy required to convert a mole of ionic solid into its constituent ions in the gas phase

the energy given off when gaseous ions combine to form one mole of an ionic solid

the energy required to produce one mole of an ionic compound from its constituent elements in their standard states

the sum of ionization energies of the components in an ionic solid

the sum of electron affinities of the components in an ionic solid

What is the electron configuration for the Fe2+ ion?

[Ar]4s03d6

[Ar]4s23d4

[Ar]4s03d8

[Ar]4s23d8

[Ar]4s63d2

The ________ ion has eight valence electrons.

Sc3+

Ti3+

V3+

Cr3+

Mn3

How many hydrogen atoms must bond to silicon to give it an octet of valence electrons?

1

2

3

4

5

n the nitrite ion (NO2-), ________.

both bonds are single bonds

both bonds are double bonds

one bond is a double bond and the other is a single bond

both bonds are the same

there are 20 valence electrons

The only noble gas without eight valence electrons is ________.

Ar

Ne

He

Kr

All noble gases have eight valence electrons.

Which atom can accommodate an octet of electrons, but doesn't necessarily have to accommodate an octet?

N

C

H

O

B