4 - 1 CH 104 Chapter 4 CH04 Chapter 5: Compounds & Bonds Valence Electrons & e- Dot Structures Octet...

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4 - 1CH 104 Chapter 4

CH04Chapter 5: Compounds & Bonds

Valence Electrons & e- Dot Structures

Octet Rule & Ions

Ionic Compounds & Formulas

Covalent Compounds & Formulas

Polyatomic Ions

Molecular Shapes & Polarity

Attractive Forces

Electron arrangement

Electrons

fill layers

around nucleus

Low High

Shells = Energy levels

2412Mg

Inner vs. valence electrons

Valence electronsThis is wheremost chemicalreactionsoccur.

Inner electronsNot much happenshere under normalconditions.

2010Ne

2311Na

2412Mg

4018Ar

Octet Rule

2010Ne

2311Na

2412Mg

4018Ar

Octet Rule

1s2, 2s11s2, 2s1 1s2, 2s21s2, 2s2

1s11s1 1s21s2

1s2, 2s2 2p61s2, 2s2 2p6

1s2, 2s2 2p6, 3s11s2, 2s2 2p6, 3s1

1s2, 2s2 2p6, 3s21s2, 2s2 2p6, 3s2[Ne] 3s1[Ne] 3s1

1s2, 2s2 2p6, 3s2 3p61s2, 2s2 2p6, 3s2 3p6

2311Na

Lewis Structures

Show only Valence

Electrons

Be B C O F NeN

2 3 4 5 6 7

2311Na

Metals give e-s to make Cations

Na11 +’s11 -’s 0

11 +’s11 -’s 0

11 +’s10 -’s 1 +

2, 8 = [Ne]2, 8 = [Ne]

Nonmetals take e-s to make Anions

17 +’s

17 -’s

17 +’s

17 -’s

17 +’s

18 -’s

17 +’s

18 -’s

3517Cl

= Cl1-

2, 8, 8 = [Ar]2, 8, 8 = [Ar]

Formation of NaCl

Na + Cl Na+ + Cl

+ and - ions attract to form an ionic bond.

e- moves from Metal Nonmetal

Metal Cation

Nonmetal Anion

Stable octets

Ionic compounds

• Not individual molecules• Form crystal arrays• Ions touch many others • Formula represents the average ion ratio

NaClsodium chloride

Common ions

TlHgAuHfLsBa

PtIrOsReWTa

RnAtPoBiPb

CdAgZrY PdRhRuTcMoNb

ZnCuTiSc NiCoFeMnCrV

In XeITeSbSn

Ga KrBrSeAsGe

Al ArClSPSi

B NeFONC

Es4 - 6

2+2+ 3+3+

4- 3-3- 2-2- 1-1-

Representative ElementsRepresentative Elements

Ionic FormulasMetal Cations + Nonmetal Anions

Na1+ Cl1-

NaClSodium Chloride

Al3+ Cl1-

AlCl3Aluminum Chloride

Common ions

RnAtPoBiPb

In XeITeSbSn

Ga KrBrSeAsGe

Al ArClSPSi

B NeFONC

HgAuHfLs PtIrOsReWTa

CdAgZrY PdRhRuTcMoNb

ZnCuTiSc NiCoFeMnCrV

2+2+ 3+3+

4- 3-3- 2-2- 1-1-

Transition ElementsTransition Elements

VariableVariable

Representative ElementsRepresentative Elements

Information in the table

55.845

Elemental Symbol

Electronic Configuration

Atomic mass (weight)26

[Ar]3d64s2

Atomic number

Name of the element

Oxidation states (Valence)Oxidation states (Valence)

Transition Metal Ions

Fe2+ Cl1-

Iron (II) Chloride

Fe3+ Cl1-

Iron (III) Chloride

Cl1- Cl1-

Ferrous Chloride Ferric Chloride

Ionic compoundsC

Anions

Br1- O2- N3-

NaBr Na2O Na3N

FeBr3 Fe2O3FeN

CuBr Cu2O Cu3N

Sodium Bromide Sodium Oxide Sodium Nitride

Magnesium Bromide

Aluminum Bromide

Iron (III) BromideFerric Bromide

Copper (I) BromideCuprous Bromide

Magnesium Oxide

Aluminum Oxide

Iron (III) OxideFerric Oxide

Copper (I) OxideCuprous Oxide

Magnesium Nitride

Aluminum Nitride

Iron (III) NitrideFerric Nitride

Copper (I) NitrideCuprous Nitride

Be B C O F NeN

2 3 4 5 6 7

Metals give e-s to nonmetalsMetals give e-s to nonmetals

Nonmetals Share e-s

with other nonmetals

Nonmetals Share e-s

with other nonmetals

Covalent Bonds

H H+ H H

+ Cl Cl

+N N N N

Covalent Bonds

H-H H2 Cl-Cl Cl2

O=O O2

N N N2

Covalent Bonds

COCarbon monoxide

Carbon dioxide CO2

May modify rules to improve sound. ie - monoxide not monooxide.

Naming covalent compounds

May modify rules to improve the sound. Example - use monoxide not monooxide.

carbon tetrachloride

diphophorous pentoxide

iodine trichloride

silicon dioxide

carbon monoxidecarbon dioxide

dinitrogen pentoxide

Covalent compounds•Discrete molecular units•Atoms held together by bonds•Covalent compounds exist in all states

(CO2 - gas, H2O - liquid, SiO2 - solid)

•Formula represents atoms in a molecule

Properties of ionic and covalent compounds

Lewis Structures for Molecules & Polyatomic Ions

Practice drawing electron dot (Lewis) structures for the following:

Notice options for Resonance Structures:

Polyatomic Ions

Na1+ SO42-

Na2SO4

Sodium Sulfate

NH41+ PO4

(NH4)3PO4

Ammonium Phosphate

Polyatomic Ions

Ca2+ C2H3O21-

Calcium Acetate

Sn2+ NO21-

Sn(NO2)2

Tin (II) Nitrite

C2H3O21-

Ca(C2H3O2)2

Stannous Nitrite

Naming Practice

Aluminum Flouride

NaHCO3

Iron (III) Flouride or Ferric Flouride

Nitrogen Triflouride

Sulfur Trioxide

Potassium Sulfite

Magnesium Carbide

Calcium CarbonateSodium Hydrogen CarbonateSodium Bicarbonate

Bond Polarity, Electronegativity

ClH ClH

Electrons in covalent bonds rarely get shared equally.

Electronegativity

Relative ability of atoms to attract e-.

Li Be B C

4 - 50

Electronegativity

Relative ability of atoms to attract e-.

Li Be B C

4 - 50

4.03.53.0

2.1 2.5

0.9 1.8

1.5 2.0

ElectronegativityRelative ability of atoms to attract electrons.

Periodic trends

ClH2.1 3.0

Polar Covalent

Electronegativity Difference

< 0.5 Nonpolar

0.5-1.7 Polar

>1.8 Ionic

Bond Polarity, Electronegativity

Polarity, Shape

3.5 3.52.5

O=C=Od+ d-d-

Polar Covalent Bonds

Linear Shape (180o)Linear Shape (180o)

Electronegativity Difference

< 0.5 Nonpolar

0.5-1.7 Polar

>1.8 Ionic

Nonpolar Compound

Polarity, Shape (VSEPR)

O=C=Od+ d-d-

e-’s in 2 directions = 180o

Linear

e-’s in 3 directions = 120o

d- Trigonal planar

Nonpolar Compound

Polar Compound

2.12.1

(~109o)Tetrahedral

e-’s in 4 directions = 109.5o

(105o)Tetrahedral Configuration of Electrons

Bent Configuration of Atoms

(105o)Tetrahedral Configuration of Electrons

Bent Configuration of Atoms

e-’s in 4 directions = 109.5o

NH HH d+

d-e-’s in 4 directions = 109.5o

Pyramidal

(~109.5o 107o)Tetrahedral Configuration of Electrons

Trigonal Pyramid Configuration of Atoms

(~109.5o 107o)Tetrahedral Configuration of Electrons

Trigonal Pyramid Configuration of Atoms

Tetrahedral electron-pair Geometries

Tetrahedral

PyramidalBent

Exceptions to Octet Rule

2.0 d+d- d-

Polar Covalent Bonds

(120o)Trigonal Planar

Nonpolar Compound

Exceptions to Octet Rule

Trigonal BipyramidTrigonal Bipyramid

ClClCl

OctahedralOctahedral

Some common geometries

e- pairs aroundShape central atom Example

Linear 2 BeH2, HF

Trigonal plane 3 BF3

Tetrahedral 4 CH4

Pyramidal 4 NH3

Bent 4 H2O

Geometry and polar molecules

For a molecule to be polar- must have polar bonds- must have the proper geometry

CH4 non-polarCH3Cl polarCH2Cl2 polarCHCl3 polarCCl4 non-polar

Properties of ionic & covalent compounds

Ionic compounds•Exist as 3-D network of ions•Held together by electrostatic attraction

•Ionic compounds are solids at room temp.

•Formula is simple average

Covalent compounds•Discrete molecular units•Atoms held together by covalent bonds

•Covalent compounds exist in all states(CO2 - gas, H2O - liquid, SiO2 - solid)

Covalent compounds•Discrete molecular units•Atoms held together by bonds•Covalent compounds exist in all states

(CO2 - gas, H2O - liquid, SiO2 - solid)

Properties of ionic and covalent compounds

Attractive ForcesIonic Bonds 150 - 3000 kcal

mol150 - 3000 kcalmol

Melting PointNaCl 801oC

Na2S 920oC

MgF2 1248oC

Melting PointNaCl 801oC

Na2S 920oC

MgF2 1248oC

Ionic compounds•Held together by electrostatic attraction

•Ionic compounds are solids at room temp

Boiling PointNaCl 1413oC

H HOd-

Attractive ForcesIon-Dipole

Od- d+

H Cld+ d-

Attractive Forces

Dipole-Dipole 0.1 - 1 kcalmol0.1 - 1 kcalmol

Melting PointHCl -114oC

CH3F -142oC

Melting PointHCl -114oC

CH3F -142oC

H Cld+ d-

Boiling PointHCl -85oC

F Fd+ d-

Fd+ d-

Attractive ForcesInduced dipole – Induced dipole(Dispersion Forces) 0.01 kcal

mol0.01 kcalmol

Melting Point

F2 -220oC

CH4 -183oC

Melting Point

F2 -220oC

CH4 -183oC

Fd+ d-

Boiling Point

F2 -188oC

CH4 -162oC

Boiling Point

F2 -188oC

CH4 -162oC

Dipole-Induced Dipole Attractive Forces

Id+ d-

H HOd-

Od+ d+

Polar Attraction

Attractive Forces

Hydrogen Bonds

Hydrogen Bonding of Water

Hydrogen Bonds

5 - 10 kcalmol5 - 10 kcalmol

Melting Point

H2O 0oC

NH3 -78oC

Melting Point

H2O 0oC

NH3 -78oC

Boiling Point

H2O 100oC

NH3 -33oC

Boiling Point

H2O 100oC

NH3 -33oC

Frozen H2O: Slow moving moleculesH-Bond in patterns

Hydrogen Bonding of Water

Boiling and melting points

Chemical Bond Mp Bp N2 Nonpolar -210 -196 O2 Nonpolar -219 -183 NH3 Polar -78 -33 H2O Polar 0 100NaCl Ionic 804 1413

Melting and Boiling points•Very high for ionic compounds•Typically lower for covalent compounds

Polarity and solubilitySolubility The maximum amount of a solute

that dissolves in a given solvent

Depends on the forces of attraction between molecules - intermolecular

Types of intermolecular attractions most often encountered• Dipole-Dipole• Hydrogen bonding• Van der Wall forces

General rule“Like dissolves like”

4 - 62CH 104 Chapter 462

Flowchart for Naming Ionic Compounds

4 - 63CH 104 Chapter 463

A. The Group number for sulfur is

1) 4A(14) 2) 8A(18) 3) 6A(16)

B. The number of valence electrons in sulfur is

1) 4e 2) 6e 3) 8e

C. The change in electrons for an octet requires a

1) gain of 2e 2) loss of 2e 3) a gain of 4e

D. The ionic charge of sulfur is

1) 2+ 2) 2 3) 4

Learning Check

A. The Group number for sulfur is

1) 4A(14) 2) 8A(18) 3) 6A(16)

B. The number of valence electrons in sulfur is

1) 4e 2) 6e 3) 8e

C. For Sulfur to form an octet requires a

1) gain of 2e 2) loss of 2e 3) a gain of 4e

D. The ionic charge of sulfur is

1) 2+ 2) 2 3) 4 64

Solution

4 - 65CH 104 Chapter 465

Select the larger atom or ion in the following:

1. A.) Mg or B.) Mg2+

2. A.) S or B.) S2

3. A.) Br or B.) Br

Learning Check

4 - 66CH 104 Chapter 466

Solution

Select the larger atom or ion in the following:

1. A.) Mg or B.) Mg2+

2. A.) S or B.) S2

3. A.) Br or B.) Br

4 - 67CH 104 Chapter 467

Select the correct formula for each of the following ionic compounds:

A. Na+ and S2–

1) NaS 2) Na2S 3) NaS2

B. Al3+ and Cl–

1) AlCl3 2) AlCl 3) Al3Cl

C. Mg2+ and N3–

1) MgN 2) Mg2N3 3) Mg3N2

Learning Check

4 - 68CH 104 Chapter 468

Select the correct formula for each of the following ionic compounds:

A. Na+ and S2–

1) NaS 2) Na2S 3) NaS2

B. Al3+ and Cl–

1) AlCl3 2) AlCl 3) Al3Cl

C. Mg2+ and N3–

1) MgN 2) Mg2N3 3) Mg3N2

Solution

4 - 69CH 104 Chapter 469

Give the names of the following ions: Ba2+ Al3+ K+

_________ __________ _________

N3 O2 F

_________ __________ _________

P3 S2 Cl

_________ __________ _________

Learning Check

4 - 70CH 104 Chapter 470

Give the names of the following ions: Ba2+ Al3+ K+

barium aluminum potassium_____ ____ __________ _________

N3 O2 F

nitride oxide fluoride_________ __________ _________

P3 S2 Cl

phosphide sulfide chloride_________ __________ _________

Solution

4 - 71CH 104 Chapter 471

Write the names of the following compounds:

1) CaO ___________

2) KBr ___________

3) Al2O3 ___________

4) MgCl2 ___________

Learning Check

4 - 72CH 104 Chapter 472

Write the names of the following compounds:

1) CaO calcium oxide

2) KBr potassium bromide

3) Al2O3 aluminum oxide

4) MgCl2 magnesium chloride

Solution

4 - 73CH 104 Chapter 473

Learning Check

Write the formulas and names for compounds of the following ions:

Br– S2− N3−

4 - 74CH 104 Chapter 474

Solution

Br− S2− N3−

NaBrsodium bromide

sodium sulfide

sodium nitride

aluminum bromide

aluminum sulfide

AlNaluminum nitride

Write the formulas and names for compounds of the following ions:

4 - 75CH 104 Chapter 475

Learning Check

Select the correct name for each.A. Fe2S3

1) iron sulfide 2) iron(II) sulfide 3) iron(III) sulfide

B. CuO 1) copper oxide 2) copper(I) oxide 3) copper(II) oxide

4 - 76CH 104 Chapter 476

Solution

Select the correct name for each.A. Fe2S3

1) iron sulfide 2) iron(II) sulfide 3) iron(III) sulfide Fe3+ S2–

B. CuO 1) copper oxide 2) copper(I) oxide 3) copper(II) oxide Cu2+ O2–

4 - 77CH 104 Chapter 477

Learning Check

The correct formula for each of the following is:

A. copper(I) nitride 1) CuN 2) CuN3 3) Cu3N

B. lead(IV) oxide 1) PbO2 2) PbO 3) Pb2O4

4 - 78CH 104 Chapter 478

Solution

The correct formula for each of the following is:

A. copper(I) nitride 1) CuN 2) CuN3 3) Cu3N

3Cu+ + N3– = 3(1+) + (3–) = 0

B. lead(IV) oxide 1) PbO2 2) PbO 3) Pb2O4

Pb4+ + 2O2– = (4+) + 2(2–) = 0

4 - 79CH 104 Chapter 479

Match each formula with the correct name:

A. MgS 1) magnesium sulfite

MgSO3 2) magnesium sulfate

MgSO4 3) magnesium sulfide

B. Ca(ClO3)2 1) calcium chlorate

CaCl2 2) calcium chlorite

Ca(ClO2)2 3) calcium chloride

Learning Check

4 - 80CH 104 Chapter 480

Match each formula with the correct name:

A. MgS 1) magnesium sulfite

MgSO3 2) magnesium sulfate

MgSO4 3) magnesium sulfide

B. Ca(ClO3)2 1) calcium chlorate

CaCl2 2) calcium chlorite

Ca(ClO2)2 3) calcium chloride

Solution

4 - 81CH 104 Chapter 481

Learning Check

Name each of the following compounds:

A. Mg(NO3)2

B. Cu(ClO3)2

C. PbO2

D. Fe2(SO4)3

E. Ba3(PO3)2

4 - 82CH 104 Chapter 482

Solution

Name each of the following compounds:

A. Mg(NO3)2

B. Cu(ClO3)2

C. PbO2

D. Fe2(SO4)3

E. Ba3(PO3)2

magnesium nitrate

copper(II) chlorate

lead(IV) oxide

iron(III) sulfate

barium phosphite

4 - 83CH 104 Chapter 483

Select the correct formula for each:A. aluminum nitrate 1) AlNO3 2) Al(NO)3 3) Al(NO3)3

B. copper(II) nitrate 1) CuNO3 2) Cu(NO3)2 3) Cu2(NO3)

C. iron(III) hydroxide 1) FeOH 2) FeOH3 3) Fe(OH)3

D. tin(IV) hydroxide 1) Sn(OH)4 2) Sn(OH)2 3) Sn4(OH)

Learning Check

4 - 84CH 104 Chapter 484

Select the correct formula for each:A. aluminum nitrate 1) AlNO3 2) Al(NO)3 3) Al(NO3)3

B. copper(II) nitrate 1) CuNO3 2) Cu(NO3)2 3) Cu2(NO3)

C. iron(III) hydroxide 1) FeOH 2) FeOH3 3) Fe(OH)3

D. tin(IV) hydroxide 1) Sn(OH)4 2) Sn(OH)2 3) Sn4(OH)

Solution

4 - 85CH 104 Chapter 485

Learning Check

Write the correct formula for each:

A. potassium bromate

B. calcium carbonate

C. sodium phosphate

D. iron(III) oxide

E. iron(II) nitrite

4 - 86CH 104 Chapter 486

Solution

Write the correct formula for each:

A. potassium bromate

B. calcium carbonate

C. sodium phosphate

D. iron(III) oxide

E. iron(II) nitrite

Na3PO4

Fe(NO2)2

4 - 87CH 104 Chapter 487

Learning Check

Name the following compounds:A. Ca3(PO4)2

B. FeBr3

C. Al2S3

D. Zn(NO2)2

E. NaHCO3

4 - 88CH 104 Chapter 488

Solution

Name the following compounds:A. Ca3(PO4)2 Ca2+ PO4

3− calcium phosphate

B. FeBr3 Fe3+ Br− iron(III) bromideC. Al2S3 Al3+ S2− aluminum sulfideD. Zn(NO2)2 Zn2+ NO2

− zinc nitriteE. NaHCO3 Na+ HCO3

− sodium hydrogen carbonate

orsodium

bicarbonate

4 - 89CH 104 Chapter 489

Learning Check

Write the formulas for the following:A. calcium nitrateB. iron(II) hydroxideC. aluminum carbonateD. copper(II) bromideE. lithium phosphate

4 - 90CH 104 Chapter 490

Solution

Write the formulas for the following:A. calcium nitrate Ca2+, NO3

− Ca(NO3)2

B. iron(II) hydroxide Fe2+, OH− Fe(OH)2

C. aluminum carbonate Al3+, CO32− Al2(CO3) 3

D. copper(II) bromide Cu2+, Br− CuBr2

E. lithium phosphate Li+, PO43−

Li3PO4

4 - 91CH 104 Chapter 491

What is the name of each of the following diatomic molecules?H2 _______________

N2 _______________

Cl2 _______________

O2 _______________

I2 _______________

Learning Check

4 - 92CH 104 Chapter 492

What is the name of each of the followingdiatomic molecules?

H2 hydrogenN2 nitrogenCl2 chlorine O2 oxygenI2 iodine

Solution

4 - 93CH 104 Chapter 493

FNO2, a rocket propellant, has two resonance structures. One is shown below. What is the other resonance structure?

Learning Check

4 - 94CH 104 Chapter 494

FNO2, a rocket propellant, has two resonance structures. One is shown below. What is the other resonance structure?

Solution

4 - 95CH 104 Chapter 495

Select the correct name for each compound.A. SiCl4 1) silicon chloride

2) tetrasilicon chloride3) silicon tetrachloride

B. P2O5 1) phosphorus oxide2) phosphorus pentoxide3) diphosphorus pentoxide

C. Cl2O7 1) dichlorine heptoxide2) dichlorine oxide3) chlorine heptoxide

Learning Check

4 - 96CH 104 Chapter 496

Select the correct name for each compound.A. SiCl4 3) silicon tetrachlorideB. P2O5 3) diphosphorus pentoxideC. Cl2O7 1) dichlorine heptoxide

Solution

4 - 97CH 104 Chapter 497

Write the name of each covalent compound.

CO _____________________

CO2 _____________________

PCl3 _____________________

CCl4 _____________________

N2O _____________________

Learning Check

4 - 98CH 104 Chapter 498

Write the name of each covalent compound.CO carbon monoxideCO2 carbon dioxidePCl3 phosphorus trichlorideCCl4 carbon tetrachlorideN2O dinitrogen oxide

Solution

Guide to Writing Formulas for Covalent Compounds

4 - 100CH 104 Chapter 4100

Write the formula for carbon disulfide.

STEP 1 Elements are C and SSTEP 2 No prefix for carbon means 1 C

Prefix di = 2 Formula: CS2

Writing Formulas of Covalent Compounds

4 - 101CH 104 Chapter 4101

Write the correct formula for each of the following:A. phosphorus pentachloride

B. dinitrogen trioxide

C. sulfur hexafluoride

Learning Check

4 - 102CH 104 Chapter 4102

Write the correct formula for each of the following:A. phosphorus pentachloride

1P penta = 5Cl PCl5

B. dinitrogen trioxidedi = 2N tri = 3 O N2O3

C. sulfur hexafluoride1S hexa = 6F SF6

Solution

4 - 103CH 104 Chapter 4103

Learning Check

Identify each compound as ionic or covalent, and give its correct name.A. SO2

B. BaCl2

C. (NH4)3PO4

D. Cu2CO3

E. N2O4

4 - 104CH 104 Chapter 4104

Solution

Identify each compound as ionic or covalent, and give its correct name.

A. SO2 covalent; sulfur dioxide

B. BaCl2 ionic; barium chloride

C. (NH4)3PO3 ionic; ammonium phosphite

D. Cu2CO3 ionic; copper(I) carbonate

E. N2O4 covalent; dinitrogen tetroxide

4 - 105CH 104 Chapter 4105

Learning Check

Name the following compounds:A. Ca3(PO4)2

B. FeBr3

C. SCl2

D. Cl2O

4 - 106CH 104 Chapter 4106

Solution

Name the following compounds:

A. Ca3(PO4)2 ionic Ca2+, PO43− calcium

phosphate

B. FeBr3 ionic Fe3+, Br − iron(III) bromide

C. SCl2 covalent 1S, 2Cl sulfur dichloride

D. Cl2O covalent 2Cl, 1 O dichlorine oxide

4 - 107CH 104 Chapter 4107

Learning Check

Write the formulas for the following:A. calcium nitrateB. boron trifluorideC. aluminum carbonateD. dinitrogen tetroxideE. copper(I) phosphate

4 - 108CH 104 Chapter 4108

Solution

Write the formulas for the following:

A. calcium nitrate Ca2+, NO3−

Ca(NO3)2

B. boron trifluoride 1B, 3F BF3

C. aluminum carbonate Al3+, CO32− Al2(CO3) 3

D. dinitrogen tetroxide 2N, 4 O N2O4

E. copper(I) phosphate Cu+, PO43−

Cu3PO4

4 - 109CH 104 Chapter 4109

Use the electronegativity difference to identify the type of bond between the following:nonpolar covalent (NP), polar covalent (P), or

ionic (I) A. K–N

B. N–OC. Cl–ClD. B–Cl

Learning Check

4 - 110CH 104 Chapter 4110

Use the electronegativity difference to identify the type of bond between the following:nonpolar covalent (NP), polar covalent (P), or

ionic (I)A. K–N 2.2 ionic (I)

B. N–O 0.5 polar covalent (P)C. Cl–Cl 0.0 nonpolar covalent (NP)

D. B–Cl 1.0 polar covalent (P)

Solution

4 - 111CH 104 Chapter 4111

Learning Check

The shape of a molecule of N2O (N N O) is1) linear2) trigonal planar3) bent (120°)

4 - 112CH 104 Chapter 4112

Solution

The shape of a molecule of N2O (N N O) is1) linear

In the electron-dot structure with 16 e–, octets are acquired using two double bonds to the

central N atom. The shape of a molecule with two electron groups and two bonded atoms (no lone pairs on N) is linear.

two electron groups

• • • •

: N :: N :: O :

• • • •

: N = N=O : linear, 180°

4 - 113CH 104 Chapter 4113

Learning Check

State the number of electron groups and lone pairs, and use VSEPR theory to determine the shape of the following molecules or ions.

1) tetrahedral 2) pyramidal 3) bent

A. PF3

B. H2SC. CCl4

4 - 114CH 104 Chapter 4114

Solution

State the number of electron groups and lone pairs, and use VSEPR theory to determine the shape of the following molecules or ions. A. PF3

4 electron groups, 1 lone pair, (2) pyramidalB. H2S

4 electron groups, 2 lone pairs, (3) bentC. CCl4

4 electron groups, 0 lone pairs, (1) tetrahedral

4 - 115CH 104 Chapter 4115

Polar Molecules

A polar molecule contains polar bonds has a separation of positive and negative charge

called a dipole, indicated with + and –

has dipoles that do not cancel + –

• •

H–Cl H—N—H dipole

H dipoles do not cancel

4 - 116CH 104 Chapter 4116

Nonpolar Molecules

A nonpolar molecule contains nonpolar bonds

Cl–Cl H–H

or has a symmetrical arrangement of polar bonds

4 - 117CH 104 Chapter 4

Determining Molecular Polarity

Determine the polarity of the H2O molecule.

Solution: The four electron groups of oxygen are bonded to two H atoms. Thus the H2O molecule has a net dipole, which makes it a polar molecule.

4 - 118CH 104 Chapter 4118

Learning Check

Determine the shape of each of the following molecules and whether they are polar or nonpolar. Explain.A. PBr3

B. HBrC. Br2

D. SiBr4

4 - 119CH 104 Chapter 4119

Solution

Determine the shape of each of the following molecules and whether they are polar or nonpolar. Explain.A. PBr3 1) pyramidal; polar; dipoles don’t

cancelB. HBr 1) linear; polar; one polar bond (dipole)C. Br2 2) linear; nonpolar; nonpolar bondD. SiBr4 2) tetrahedral; nonpolar; dipoles cancel

4 - 120CH 104 Chapter 4120

Learning Check

Identify the main type of attractive forces for each:1) ionic 2) dipole–dipole 3) hydrogen bonds 4) dispersion

A. NCl3

B. H2OC. Br–BrD. KClE. NH3

4 - 121CH 104 Chapter 4121

Solution

Identify the main type of attractive forces for each:1) ionic 2) dipole–dipole3) hydrogen bonds 4) dispersion

2 A. NCl3

3 B. H2O 4 C. Br–Br 1 D. KCl 3 E. NH3

4 - 1 CH 104 Chapter 4 CH04 Chapter 5: Compounds & Bonds Valence Electrons & e- Dot Structures Octet...

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