Chapter 9 Test

Question 1

Which of the following Lewis dot structures best represents Cl −?

Answer 1

-

Question 2

The electron configuration of argon is 1s22s22p63s23p6.

How many valence electrons does argon have?

Answer 2

8

Question 3

How many electrons must be accounted for in the Lewis dot structure for the carbonate ion?

Answer 3

24

Question 4

Which of the following is the correct Lewis dot structure of carbon tetrachloride, CCl4?

Answer 4

-

Question 5

Which is the correct Lewis dot structure for H2S? In this molecule, the sulfur (S) atom has the same number of valence electrons as an oxygen atom.

Answer 5

-

Question 6

Using bond dissociation energy, approximate the enthalpy change for the combustion reaction of 2 moles octane (C8H18 ) and 25 moles oxygen (O2 ) to form carbon dioxide (CO2 ) and water (H2O).
C–C bonds (346 kJ)
C–H bonds (413 kJ)
O=O bonds (498 kJ)
C=O bonds (732 kJ)
O–H bonds (463 kJ)

Answer 6

-7238

Question 7

Arrange the following molecules or ions in the order of increasing average C–O bond order. CO, CO2, CO3−

Answer 7

CO3-, CO2, CO

Question 8

How many valence electrons are found in an atom of nitrogen?

Answer 8

5

Question 9

Which one of the following compounds would you expect to be covalent?

Answer 9

OF2

Question 10

Which of the following formulas accurately represents the binary ionic compound formed between magnesium and chlorine?

Answer 10

MgCl2

Question 11

Which one of the following binary ionic compounds is expected to have the highest lattice energy?

Answer 11

LiI

Question 12

Which of the following molecules has an odd number of valence electrons?

Answer 12

NO2

Question 13

For which of the following structures can a resonance structure be drawn?

Answer 13

-

Question 14

How many resonance structures can be drawn for a molecule whose structure is best explained by three different Lewis dot structures?

Answer 14

3

Question 15

Which statement about resonance hybrids is correct?

Answer 15

A resonance hybrid structure describes a molecule’s structure better than any of the contributing resonance structures by itself.

Question 16

To calculate the formal charge on an atom, “ownership” of each electron must first clearly be defined. That is, each electron must be assigned to one atom or another atom. What is the next major step in calculating the formal charge?

Answer 16

Subtract the number of electrons assigned to the Lewis dot structure from the sum of the number of valence electrons

Question 17

Which of the following statements is not correct?

Answer 17

An atom with a low electronegativity and a formal charge of 0 will have a tendency to acquire another electron.

Question 18

What is electronegativity?

Answer 18

Electronegativity is a quantitative measure of the tendency of an atom to attract electrons to itself.

Question 19

Which of the following statement is true regarding the water molecule?

Answer 19

The Lewis structure of water shows 2 lone pairs of electrons on oxygen.

Question 20

Which of the following correctly ranks, in order from least to greatest, the distance between bonded atoms of the same element?

Answer 20

triple bond, double bond, single bond

Question 21

Which one of the following compounds would you expect to most be ionic?

Answer 21

Na2O

Question 22

Which of the following pairs of Lewis dot structures represent correct resonance structures for nitryl chloride, ClNO2?

Answer 22

-

Question 23

How many lone pairs of electrons are in the Lewis dot structure of the azide anion, N3−?

Answer 23

4

Question 24

Draw the Lewis dot structure of ozone, O3. How many lone pair of electrons is present in the middle oxygen?

Answer 24

1

Question 25

Which of the following binary ionic compounds has the lowest lattice energy?

Answer 25

LiI