Introductory Chemistry Essentials

Problem 4

What is the difference between ionic bonding and covalent bonding?

Lottie Adams

Numerade Educator

Problem 5

Use the Lewis model to predict the chemical formula of the ionic compound formed from aluminium and chlorine.

Nicole Smina

Numerade Educator

01:13

Problem 6

What is the difference between lone pair and bonding pair electrons?

Lottie Adams

Numerade Educator

01:14

Problem 7

How are double and triple bonds physically different from single bonds?

Lottie Adams

Numerade Educator

02:02

Problem 8

What is the procedure for writing a covalent Lewis structure?

Lottie Adams

Numerade Educator

01:43

Problem 9

How do you determine the number of electrons that go into the Lewis structure of a molecule?

Lottie Adams

Numerade Educator

01:47

Problem 10

How do you determine the number of electrons that go into the Lewis structure of a polyatomic ion?

Lottie Adams

Numerade Educator

01:19

Problem 11

Why does the octet rule have exceptions? List some examples.

Lottie Adams

Numerade Educator

Problem 12

What are resonance structures? Why are they necessary?

Lottie Adams

Numerade Educator

02:27

Problem 13

Explain how VSEPR theory predicts the shapes of molecules.

Lottie Adams

Numerade Educator

02:02

Use the VSEPR theory to predict the bond angle A-X-A for the following molecules if all electrons on $\mathrm{A}$ are forming bonds with $X$ atoms and there is no lone pair:
(a) $\mathrm{A}_{2} \mathrm{X}$
(b) $\mathrm{A}_{3} \mathrm{X}$
(c) $\mathrm{A}_{4} \mathrm{X}$

Nicole Smina

Numerade Educator

00:46

Problem 15

Give the bond angles for each of the geometries in the preceding question.

Lottie Adams

Numerade Educator

Problem 16

What is the difference between electron geometry and molecular geometry in VSEPR theory?

Lottie Adams

Numerade Educator

01:12

Problem 17

What is electronegativity?

Nicole Smina

Numerade Educator

01:01

Problem 18

What is the most electronegative element on the periodic table?

Lottie Adams

Numerade Educator

00:59

Problem 19

What is a polar covalent bond?

Lottie Adams

Numerade Educator

02:28

Problem 20

What is a dipole moment?

Wilson Ma

The University of Alabama

00:57

Problem 21

Is the $\mathrm{H}-\mathrm{Cl}$ bond in $\mathrm{HCl}$ polar? Do $\mathrm{HCl}$ molecules possess a dipole moment?

Nicole Smina

Numerade Educator

Problem 22

Is the $C=O$ bond in $C O_{2}$ polar? Do $C O_{2}$ molecules possess a dipole moment?

Nicole Smina

Numerade Educator

01:04

Problem 23

Write an electron configuration for each element and the corresponding Lewis structure. Indicate which electrons in the electron configuration are included in the Lewis structure.
(a) $N$
(b) $C$
(c) Cl
(d) Ar

Lottie Adams

Numerade Educator

00:52

Problem 24

Lottie Adams

Numerade Educator

01:00

Problem 25

Write the Lewis structure for each element.
(a) $\mathrm{K}$
(b) $\mathrm{Mg}$
(c) Al
(d) Ne

Nicole Smina

Numerade Educator

01:19

Problem 26

Write the Lewis structure for each element.
(a) Kr
(b) P
(c) B
(d) $\mathrm{Na}$

Lottie Adams

Numerade Educator

00:46

Problem 27

Write a generic Lewis structure for the halogens. Do the halogens tend to gain or lose electrons in chemical reactions? How many?

Lottie Adams

Numerade Educator

00:58

Problem 28

Write a generic Lewis structure for Group 3 atoms. Do they tend to gain or lose electrons in chemical reactions? How many?

Nicole Smina

Numerade Educator

01:05

Problem 29

Write a generic Lewis structure for the alkaline earth metals. Do the alkaline earth metals tend to gain or lose electrons in chemical reactions? How many?

Lottie Adams

Numerade Educator

00:54

Problem 30

Write a generic Lewis structure for the elements in the oxygen family (Group $6 \mathrm{~A}$ ). Do the elements in the oxygen family tend to gain or lose electrons in chemical reactions? How many?

Lottie Adams

Numerade Educator

02:20

Problem 31

Write the Lewis structure for each ion.
(a) $\mathrm{Al}^{3+}$
(b) $\mathrm{Sr}^{2+}$
(c) $S e^{2-}$
(d) $\mathrm{N}^{3-}$

Nicole Smina

Numerade Educator

01:14

Problem 32

Write the Lewis structure for each ion.
(a) $\mathrm{Br}^{-}$
(b) $\mathrm{Na}^{+}$
(c) $\mathrm{P}^{3-}$
(d) $\mathrm{Mg}^{2+}$

Nicole Smina

Numerade Educator

01:13

Problem 33

Indicate the noble gas that has the same Lewis structure as each ion.
(a) $\mathrm{Br}^{-}$
(b) $\mathrm{O}^{2-}$
(c) $\mathrm{Rb}^{+}$
(d) $\mathrm{Ba}^{2+}$

Lottie Adams

Numerade Educator

Problem 34

Indicate the ion that has the same Lewis structure as argon.
(a) $\mathrm{Mg}^{2+}$
(b) $\mathrm{Cl}^{-}$
(c) $\mathrm{Ca}^{2+}$
(d) $\mathrm{Br}^{-}$

David Collins

Numerade Educator

00:45

Problem 35

Is each compound best represented by an ionic or a covalent Lewis structure?
(a) $S F_{6}$
(b) $\mathrm{MgCl}_{2}$
(c) $\operatorname{BrCl}$
(d) $\mathrm{K}_{2} \mathrm{~S}$

Nicole Smina

Numerade Educator

00:27

Problem 36

Is each compound best represented by an ionic or a covalent Lewis structure?
(a) $\mathrm{LiCl}$
(b) $\mathrm{MgO}$
(c) $\mathrm{K}_{2} \mathrm{O}$
(d) $\mathrm{Al}_{2} \mathrm{O}_{3}$

Nicole Smina

Numerade Educator

Problem 37

Write the Lewis structure for each ionic compound.
(a) NaF
(b) $\mathrm{CaO}$
(c) $\operatorname{SrBr}_{2}$
(d) $\mathrm{K}_{2} \mathrm{O}$

Lottie Adams

Numerade Educator

01:47

Problem 38

Write the Lewis structure for each ionic compound.
(a) $\mathrm{LiCl}$
(b) $\mathrm{MgO}$
(c) $\mathrm{K}_{2} \mathrm{O}$
(d) $\mathrm{Al}_{2} \mathrm{O}_{3}$

David Collins

Numerade Educator

01:05

Problem 39

Use the Lewis model to determine the formula for the compound that forms from each pair of atoms.
(a) $\mathrm{Ca}$ and $\mathrm{S}$
(b) $\mathrm{Mg}$ and $\mathrm{Br}$
(c) $\mathrm{Cs}$ and $\mathrm{I}$
(d) $C a$ and $N$

Lottie Adams

Numerade Educator

00:58

Problem 40

Use the Lewis model to determine the formula for the compound that forms from each pair of atoms.
(a) $\mathrm{Al}$ and $\mathrm{S}$
(b) $\mathrm{Na}$ and $\mathrm{S}$
(c) $\mathrm{Sr}$ and $\mathrm{Se}$
(d) Ba and F

Lottie Adams

Numerade Educator

01:18

Problem 41

Which of the following pairs of elements forms an ionic compound with the formula $\mathrm{MX}_{2} ?$
(a) $\mathrm{Na}$ and $\mathrm{O}$
(b) $\mathrm{Mg}$ and $\mathrm{Cl}$
(c) $C$ and $O$

Nicole Smina

Numerade Educator

01:24

Problem 42

Which of the following pairs of elements forms an ionic compound with the formula $\mathrm{M}_{2} \mathrm{X}_{3} ?$
(a) $\mathrm{K}$ and $\mathrm{S}$
(b) $\mathrm{Mg}$ and $\mathrm{O}$
(c) $\mathrm{Al}$ and $\mathrm{O}$

Nicole Smina

Numerade Educator

01:36

Problem 43

Determine what is wrong with each ionic Lewis structure and write the correct structure.
(a) $[\mathrm{Cs}:]^{+}[: \ddot{\mathrm{Cl}}:]^{-}$
(b) $\mathrm{Ba}^{+}[: \ddot{\mathrm{O}}:]^{-}$

David Collins

Numerade Educator

Problem 44

Determine the general formula of the ionic compound formed from the following pairs of elements:
(a) an alkali metal and a halogen
(b) an alkaline earth metal and a halogen
(c) an alkaline earth metal and oxygen

Nicole Smina

Numerade Educator

Problem 45

Use the Lewis model to explain why each element exists as a diatomic molecule.
(a) hydrogen
(b) iodine
(c) nitrogen
(d) oxygen

Lottie Adams

Numerade Educator

01:42

Problem 46

Use the Lewis model to explain why the compound that forms between hydrogen and sulfur has the formula $\mathrm{H}_{2} \mathrm{~S}$. Would you expect HS to be stable? $\mathrm{H}_{3} \mathrm{~S}$ ?

David Collins

Numerade Educator

01:06

Problem 47

Write the Lewis structure for each molecule.
(a) $\mathrm{PH}_{3}$
(b) $\mathrm{SCl}_{2}$
(c) $\mathrm{F}_{2}$
(d) HI

Lottie Adams

Numerade Educator

02:04

Problem 48

Write the Lewis structure for each molecule.
(a) $\mathrm{lCl}$
(b) $\mathrm{SiCl}_{4}$
(c) $\mathrm{NH}_{3}$
(d) $\mathrm{H}_{2} \mathrm{O}_{2}$

David Collins

Numerade Educator

Problem 49

Write the Lewis structure for each molecule.
(a) $\mathrm{O}_{2}$
(b) $\mathrm{CO}$
(c) HONO (N is central; H bonded to one of the O atoms.)
(d) $\mathrm{SO}_{2}$

Lottie Adams

Numerade Educator

02:52

Problem 50

Write the Lewis structure for each molecule
(a) $\mathrm{N}_{2} \mathrm{O}$ (oxygen is terminal)
(b) $\mathrm{SiH}_{4}$
(c) $\mathrm{CI}_{4}$
(d) $\mathrm{Cl}_{2} \mathrm{CO}$ (carbon is central)

David Collins

Numerade Educator

01:31

Problem 51

Write the Lewis structure for each molecule.
(a) $\mathrm{C}_{2} \mathrm{H}_{2}$
(b) $\mathrm{C}_{2} \mathrm{H}_{4}$
(c) $\mathrm{N}_{2} \mathrm{H}_{2}$
(d) $\mathrm{N}_{2} \mathrm{H}_{4}$

Lottie Adams

Numerade Educator

Problem 52

Write the Lewis structure for each molecule.
(a) $\mathrm{H}_{2} \mathrm{CO}$ (carbon is central)
(b) $\mathrm{H}_{3} \mathrm{COH}$ (carbon and oxygen are both central)
(c) $\mathrm{H}_{3} \mathrm{COCH}_{3}$ (oxygen is between the two carbon atoms)
(d) $\mathrm{H}_{2} \mathrm{O}_{2}$

Lottie Adams

Numerade Educator

00:47

Problem 53

Determine what is wrong with each Lewis structure and write the correct structure.

Lottie Adams

Numerade Educator

00:47

Problem 54

Determine what is wrong with each Lewis structure and write the correct structure.

Lottie Adams

Numerade Educator

02:00

Problem 55

Write the Lewis structure for each molecule or ion. Include resonance structures if necessary.
(a) $\mathrm{SeO}_{2}$
(b) $\mathrm{CO}_{3}^{2-}$
(c) $\mathrm{ClO}^{-}$
(d) $\mathrm{ClO}_{2}^{-}$

Lottie Adams

Numerade Educator

07:02

Problem 56

Write the Lewis structure for each molecule or ion. Include resonance structures if necessary.
(a) $\mathrm{H}_{3} \mathrm{PO}_{4}$
(b) $\mathrm{H}_{2} \mathrm{PO}_{4}$
(c) $\mathrm{HPO}_{4}^{2}$
(d) $\mathrm{PO}_{4}^{3-}$

David Collins

Numerade Educator

06:28

Problem 57

7. Write the Lewis structure for each ion. Include resonance
structures if necessary.
(a) $\mathrm{ClO}_{3}$
(b) CN
(c) $\mathrm{NO}_{2}$
(d) $\mathrm{SO}_{3}^{2-}$

David Collins

Numerade Educator

02:04

Problem 58

Write the Lewis structure for each ion. Include resonance structures if necessary.
(a) $\mathrm{SO}_{4}{ }^{2-}$
(b) $\mathrm{HSO}_{4}^{-}$ (S is central; $\mathrm{H}$ is attached to one of the $\mathrm{O}$ atoms $)$
(c) $\mathrm{NH}_{4}{ }^{+}$
(d) $\mathrm{BrO}_{2}^{-}(\mathrm{Br}$ is central $)$

Lottie Adams

Numerade Educator

02:27

Problem 59

Write the Lewis structure for each molecule. These molecules do not follow the octet rule.
(a) $\mathrm{CO}$
(b) NO
(c) $\mathrm{BF}_{3}$

David Collins

Numerade Educator

Problem 60

Write the Lewis structure for each molecule. These molecules do not follow the octet rule.
(a) $\mathrm{BBr}_{3}$
(b) NO

Lottie Adams

Numerade Educator

01:41

Problem 61

Determine the number of electron groups around the central atom for each molecule.
(a) $\mathrm{OF}_{2}$
(b) $\mathrm{NF}_{3}$
(c) $\mathrm{CS}_{2}$
(d) $\mathrm{CH}_{4}$

Lottie Adams

Numerade Educator

02:21

Problem 62

Determine the number of electron groups around the central atom for each molecule.
(a) $\mathrm{CH}_{2} \mathrm{Cl}_{2}$
(b) $\mathrm{SBr}_{2}$
(c) $\mathrm{H}_{2} \mathrm{~S}$
(d) $\mathrm{PCl}_{3}$

Lottie Adams

Numerade Educator

02:15

Problem 63

Determine the number of bonding groups and the number of lone pairs for each of the molecules in Problem $61 .$ The sum of these should equal your answers to Problem $61 .$

Lottie Adams

Numerade Educator

02:23

Problem 64

Determine the number of bonding groups and the number of lone pairs for each of the molecules in Problem $62 .$ The sum of these should equal your answers to Problem 62 .

Lottie Adams

Numerade Educator

01:54

Problem 65

Determine the molecular geometry of each molecule.
(a) $\mathrm{CBr}_{4}$
(b) $\mathrm{H}_{2} \mathrm{CO}$
(c) $\mathrm{CS}_{2}$
(d) $\mathrm{BH}_{3}$

Lottie Adams

Numerade Educator

02:25

Problem 66

Determine the molecular geometry of each molecule.
(a) $\mathrm{C}_{2} \mathrm{H}_{2}$
(b) $\mathrm{SO}_{2}$
(c) $\mathrm{CCl}_{4}$
(d) $\mathrm{NCl}_{3}$

David Collins

Numerade Educator

00:54

Problem 67

Determine the bond angles for each molecule in Problem $65 .$

Lottie Adams

Numerade Educator

Problem 68

Determine the bond angles for each molecule in Problem 66 .

Lottie Adams

Numerade Educator

01:42

Problem 69

Determine the electron and molecular geometries of each molecule.
(a) $\mathrm{N}_{2} \mathrm{O}$ (oxygen is terminal)
(b) $\mathrm{SO}_{2}$
(c) $\mathrm{H}_{2} \mathrm{~S}$
(d) $\mathrm{PF}_{3}$

Lottie Adams

Numerade Educator

01:41

Problem 70

Determine the electron and molecular geometries of each molecule. (Hint: Determine the geometry around each of the two central atoms.)
(a) $\mathrm{C}_{2} \mathrm{H}_{2}$ (skeletal structure $\mathrm{HCCH}$ )
(b) $\mathrm{C}_{2} \mathrm{H}_{4}$ (skeletal structure $\mathrm{H}_{2} \mathrm{CCH}_{2}$ )
(c) $\mathrm{C}_{2} \mathrm{H}_{6}$ (skeletal structure $\mathrm{H}_{3} \mathrm{CCH}_{3}$ )

Lottie Adams

Numerade Educator

01:01

Problem 71

Determine the bond angles for each molecule in Problem $69 .$

Lottie Adams

Numerade Educator

00:59

Problem 72

Determine the bond angles for each molecule in Problem $70 .$

Lottie Adams

Numerade Educator

01:19

Problem 73

Determine the electron and molecular geometries of each molecule. For molecules with two central atoms, indicate the geometry about each central atom.
(a) $\mathrm{N}_{2}$
(b) $\mathrm{N}_{2} \mathrm{H}_{2}$ (skeletal structure HNNH)
(c) $\mathrm{N}_{2} \mathrm{H}_{4}$ (skeletal structure $\mathrm{H}_{2} \mathrm{NNH}_{2}$ )

Lottie Adams

Numerade Educator

01:30

Problem 74

Determine the electron and molecular geometries of each molecule. For molecules with more than one central atom, indicate the geometry about each central atom.
(a) $\mathrm{CH}_{3} \mathrm{OH}$ (skeletal structure $\mathrm{H}_{3} \mathrm{COH}$ )
(b) $\mathrm{H}_{3} \mathrm{COCH}_{3}$ (skeletal structure $\mathrm{H}_{3} \mathrm{COCH}_{3}$ )
(c) $\mathrm{H}_{2} \mathrm{O}_{2}$ (skeletal structure HOOH)

Lottie Adams

Numerade Educator

02:16

Problem 75

Determine the molecular geometry of each polyatomic ion.
(a) $\mathrm{CO}_{3}^{2-}$
(b) $\mathrm{ClO}_{2}^{-}$
(c) $\mathrm{NO}_{3}^{-}$
(d) $\mathrm{NH}_{4}^{+}$

Lottie Adams

Numerade Educator

01:51

Problem 76

Determine the molecular geometry of each polyatomic ion or molecule.
(a) $\mathrm{SO}_{2}$
(b) $\mathrm{SO}_{3}$
(c) $\mathrm{SO}_{4}^{2-}$

David Collins

Numerade Educator

Problem 77

Refer to Figure 10.2 to determine the electronegativity of each element
(a) $\mathrm{Mg}$
(b) Si
(c) Br

Lottie Adams

Numerade Educator

01:44

Problem 78

Refer to Figure 10.2 to determine the electronegativity of each element.
(a) $\mathrm{F}$
(b) $C$
(c) S

Lottie Adams

Numerade Educator

00:42

Problem 79

List these elements in order of decreasing electronegativity:
$\mathrm{Rb}, \mathrm{Si}, \mathrm{Cl}, \mathrm{Ca}, \mathrm{Ga}$.

Lottie Adams

Numerade Educator

00:40

Problem 80

List these elements in order of increasing electronegativity: $\mathrm{Ba}, \mathrm{N}, \mathrm{F}, \mathrm{Si}, \mathrm{Cs}$.

Lottie Adams

Numerade Educator

Problem 81

Refer to Figure 10.2 to find the electronegativity difference between each pair of elements; then refer to Table 10.2 to classify the bonds that occur between them as pure covalent, polar covalent, or ionic.
(a) $\mathrm{Mg}$ and $\mathrm{Br}$
(b) $\mathrm{Cr}$ and $\mathrm{F}$
(c) $\mathrm{Br}$ and $\mathrm{Br}$
(d) $\mathrm{Si}$ and $\mathrm{O}$

Lottie Adams

Numerade Educator

Problem 82

Refer to Figure 10.2 to find the electronegativity difference between each pair of elements; then refer to Table 10.2 to classify the bonds that occur between them as pure covalent, polar covalent, or ionic.
(a) $K$ and $C l$
(b) $\mathrm{N}$ and $\mathrm{N}$
(c) $C$ and $S$
(d) $C$ and $C l$

David Collins

Numerade Educator

Problem 83

Arrange these diatomic molecules in order of increasing bond polarity: $\mathrm{CH}_{4}, \mathrm{NH}_{3}, \mathrm{H}_{2}, \mathrm{HF}$

David Collins

Numerade Educator

00:55

Problem 84

Arrange these diatomic molecules in order of decreasing bond polarity: $\mathrm{HCl}, \mathrm{NO}, \mathrm{F}_{2}, \mathrm{HI}$

Lottie Adams

Numerade Educator

01:08

Problem 85

Classify each diatomic molecule as polar or nonpolar.
(a) CO
(b) $\mathrm{O}_{2}$
(c) $\mathrm{F}_{2}$
(d) HBr

Lottie Adams

Numerade Educator

01:04

Problem 86

Which of the following elements are $\mathrm{m}$ than nitrogen?
(a) $C$
(b) $\mathrm{O}$
(c) Cl
(d) $\mathrm{H}$

David Collins

Numerade Educator

00:45

Problem 87

For each polar molecule in Problem 85 draw the molecule and indicate the positive and negative ends of the dipole moment.

Lottie Adams

Numerade Educator

00:41

Problem 88

For each polar molecule in Problem 86 draw the molecule and indicate the positive and negative ends of the dipole moment.

Lottie Adams

Numerade Educator

01:49

Problem 89

Classify each molecule as polar or nonpolar.
(a) $\mathrm{CS}_{2}$
(b) $\mathrm{SO}_{2}$
(c) $\mathrm{CH}_{4}$
(d) $\mathrm{CH}_{3} \mathrm{Cl}$

Lottie Adams

Numerade Educator

01:52

Problem 90

Classify each molecule as polar or nonpolar.
(a) HCl
(b) $\mathrm{Cl}_{2}$
(c) $\mathrm{CCl}_{4}$
(d) $\mathrm{CHCl}_{3}$

David Collins

Numerade Educator

Problem 91

Classify each molecule as polar or nonpolar.
(a) $\mathrm{BH}_{3}$
(b) $\mathrm{CHCl}_{3}$
(c) $\mathrm{C}_{2} \mathrm{H}_{2}$
(d) $\mathrm{NH}_{3}$

Lottie Adams

Numerade Educator

02:36

Problem 92

Classify each molecule as polar or nonpolar.
(a) $\mathrm{SiCl}_{4}$
(b) $\mathrm{SiH}_{3} \mathrm{Cl}$
(c) $\mathrm{SO}_{2}$
(d) $\mathrm{SO}_{3}$

David Collins

Numerade Educator

01:29

Problem 93

Write electron configurations and Lewis structures for each element. Indicate which of the electrons in the electron configuration are shown in the Lewis structure.
(a) Ca
(b) Ga
(c) As
(d) I

Lottie Adams

Numerade Educator

Problem 94

Write electron configurations and Lewis structures for each element. Indicate which of the electrons in the electron configuration are shown in the Lewis structure.
(a) Rb
(b) Ge
(c) $\mathrm{Kr}$
(d) Se

Lottie Adams

Numerade Educator

01:14

Problem 95

Determine whether each compound is ionic or covalent and write the appropriate Lewis structure.
(a) $\mathrm{K}_{2} \mathrm{~S}$
(b) CHFO (carbon is central)
(c) $\mathrm{MgSe}$
(d) $\mathrm{PBr}_{3}$

Lottie Adams

Numerade Educator

02:17

Problem 96

Determine whether each compound is ionic or covalent and write the appropriate Lewis structure.
(a) HCN
(b) ClF
(c) $\mathrm{MgI}_{2}$
(d) $\mathrm{CaS}$

David Collins

Numerade Educator

00:51

Problem 97

Write the Lewis structure for $\mathrm{OCCl}_{2}$ (carbon is central) and determine whether the molecule is polar. Draw the three-dimensional structure of the molecule.

Lottie Adams

Numerade Educator

01:41

Problem 98

Write the Lewis structure for $\mathrm{CH}_{3} \mathrm{COH}$ and determine whether the molecule is polar. Draw the three-dimensional structure of the molecule. The skeletal structure is:

David Collins

Numerade Educator

01:15

Problem 99

Indicate the geometry around each carbon atom of 1 -butene $\left(\mathrm{CH}_{2}=\mathrm{CHCH}_{2} \mathrm{CH}_{3}\right),$ and estimate the two $\mathrm{C}-\mathrm{C}-\mathrm{C}$ angles.

David Collins

Numerade Educator

Problem 100

0. Write the Lewis structure for benzene, $\mathrm{C}_{6} \mathrm{H}_{6},$ and draw a three-dimensional sketch of the molecule. The skeletal structure is the ring shown here.

David Collins

Numerade Educator

00:58

Problem 101

Consider the neutralization reaction. $$ \mathrm{HCl}(a q)+\mathrm{NaOH}(a q) \longrightarrow \mathrm{H}_{2} \mathrm{O}(l)+\mathrm{NaCl}(a q) $$ Write the reaction showing the Lewis structures of each of the reactants and products.

Lottie Adams

Numerade Educator

01:50

Problem 102

Consider the precipitation reaction. $$ \mathrm{Pb}\left(\mathrm{NO}_{3}\right)_{2}(a q)+2 \mathrm{LiCl}(a q) \longrightarrow \mathrm{PbCl}_{2}(\mathrm{~s})+2 \mathrm{LiNO}_{3}(a q) $$ Write the reaction showing the Lewis structures of each of the reactants and products.

Lottie Adams

Numerade Educator

01:06

Problem 103

Consider the redox reaction. $$ 2 \mathrm{~K}(s)+\mathrm{Cl}_{2}(g) \longrightarrow 2 \mathrm{KCl}(s) $$ Draw the Lewis structure for each reactant and product and determine which reactant was oxidized and which one was reduced.

Lottie Adams

Numerade Educator

00:57

Problem 104

Consider the redox reaction. $$ \mathrm{Ca}(s)+\mathrm{Br}_{2}(g) \longrightarrow \mathrm{CaBr}_{2}(s) $$ Draw the Lewis structure for each reactant and product and determine which reactant was oxidized and which one was reduced.

Lottie Adams

Numerade Educator

05:28

Problem 105

Each compound listed contains both ionic and covalent bonds. Write the ionic Lewis structure for each one including the covalent structure for the polyatomic ion. Write resonance structures if necessary.
(a) KOH
(b) $\mathrm{KNO}_{3}$
(c) LiIO
(d) $\mathrm{BaCO}_{3}$

David Collins

Numerade Educator

08:43

Problem 106

Each of the compounds listed contains both ionic and covalent bonds. Write an ionic Lewis structure for each one, including the covalent structure for the polyatomic ion. Write resonance structures if necessary.
(a) $\mathrm{Li}_{2} \mathrm{CO}_{3}$
(b) $\mathrm{NaHSO}_{4}$
(c) $\mathrm{K}_{2} \mathrm{SO}_{3}$
(d) $\mathrm{NaNO}_{2}$

David Collins

Numerade Educator

02:37

Problem 107

Each molecule listed contains an expanded octet (10 or 12 electrons) around the central atom. Write the Lewis structure for each molecule.
(a) $\mathrm{PF}_{5}$
(b) $\mathrm{SF}_{4}$
(c) $\operatorname{SeF}_{4}$

Lottie Adams

Numerade Educator

02:57

Problem 108

Each molecule listed contains an expanded octet (10 or 12 electrons) around the central atom. Write the Lewis structure for each molecule.
(a) $\mathrm{lF}_{3}$
(b) $\mathrm{POCl}_{3}$
(c) $S F_{6}$

David Collins

Numerade Educator

Problem 109

Formic acid is responsible for the sting you feel when stung by fire ants. By mass, formic acid is $26.10 \%$ C $4.38 \% \mathrm{H},$ and $69.52 \%$ O. The molar mass of formic acid is $46.02 \mathrm{~g} / \mathrm{mol}$. Find the molecular formula of formic acid and draw its Lewis structure.

Lottie Adams

Numerade Educator

03:11

Problem 110

Sodium azide has the formula of NaNx with a high nitrogen content of $64.6 \%$ by mass. Calculate the value of $x$ and predict the geometry of the azide ion.

David Collins

Numerade Educator

00:49

Problem 111

Free radicals are molecules that contain an odd number of valence electrons and therefore contain an unpaired electron in their Lewis structure. Write the best possible Lewis structure for the free radical HOO. Does the Lewis model predict that $\mathrm{HOO}$ is stable? Predict its geometry.

Lottie Adams

Numerade Educator

01:04

Problem 112

Iodine can form a series of polyiodide ions. The simplest polyiodide is triiodide $\mathrm{I}_{3}^{-}$ with a linear molecular geometry. Propose a Lewis structure for $\mathrm{I}_{3}^{-}$ What is the electron geometry around the central iodine atom?

David Collins

Numerade Educator

02:16

Problem 113

Some theories on aging suggest that free radicals cause a variety of diseases and aging. Free radicals (as explained in Problems 111 and 112 ) are molecules or ions containing an unpaired electron. As you know from the Lewis model, such molecules are not chemically stable and quickly react with other molecules. Free radicals may attack molecules within the cell, such as DNA, changing them and causing cancer or other diseases. Free radicals may also attack molecules on the surfaces of cells, making them appear foreign to the body's immune system. The immune system then attacks the cell and destroys it, weakening the body. Draw the Lewis structure for each of these free radicals, which have been implicated in theories of aging.
(a) $\mathrm{O}_{2}^{-}$
(b) $\mathrm{O}^{-}$
(c) OH
(d) $\mathrm{CH}_{3} \mathrm{OO}$ (unpaired electron on terminal oxygen)

Lottie Adams

Numerade Educator

01:37

Problem 114

Free radicals (see Problem 113) are important in many environmentally significant reactions. For example, photochemical smog, which forms as a result of the action of sunlight on air pollutants, is formed in part by these two steps: $$ \begin{array}{l}\mathrm{NO}_{2} \stackrel{\text { UV light }}{\longrightarrow}\mathrm{NO}+\mathrm{O} \\\mathrm{O}+\mathrm{O}_{2} \longrightarrow \mathrm{O}_{3}\end{array}$$
The product of this reaction, ozone, is a pollutant in the lower atmosphere. Ozone is an eye and lung irritant and also accelerates the weathering of rubber products. Write Lewis structures for each of the reactants and products in the preceding reactions.

Lottie Adams

Numerade Educator

00:46

Problem 115

Examine the formulas and space-filling models of the molecules shown here. Determine whether the structure is correct. If the structure is incorrect, sketch the correct structure.

Lottie Adams

Numerade Educator