Ch.9 - Bonding & Molecular StructureSee all chapters
All Chapters
Ch.1 - Intro to General Chemistry
Ch.2 - Atoms & Elements
Ch.3 - Chemical Reactions
BONUS: Lab Techniques and Procedures
BONUS: Mathematical Operations and Functions
Ch.4 - Chemical Quantities & Aqueous Reactions
Ch.5 - Gases
Ch.6 - Thermochemistry
Ch.7 - Quantum Mechanics
Ch.8 - Periodic Properties of the Elements
Ch.9 - Bonding & Molecular Structure
Ch.10 - Molecular Shapes & Valence Bond Theory
Ch.11 - Liquids, Solids & Intermolecular Forces
Ch.12 - Solutions
Ch.13 - Chemical Kinetics
Ch.14 - Chemical Equilibrium
Ch.15 - Acid and Base Equilibrium
Ch.16 - Aqueous Equilibrium
Ch. 17 - Chemical Thermodynamics
Ch.18 - Electrochemistry
Ch.19 - Nuclear Chemistry
Ch.20 - Organic Chemistry
Ch.22 - Chemistry of the Nonmetals
Ch.23 - Transition Metals and Coordination Compounds

Dipole Moment

See all sections
Sections
Chemical Bonds
Lattice Energy
Lattice Energy Application
Born Haber Cycle
Dipole Moment
Lewis Dot Structure
Octet Rule
Formal Charge
Resonance Structures
Additional Practice
Bond Energy

Dipole arrows are used anytime a molecule possesses a dipole moment, which happens when a molecule is polar. 

Electronegativity

Concept #1: Understanding Electronegativity

Electronegativity measures how likely an element within a bond will attract electrons more or less to itself. 

Dipole Arrows

Concept #2: Understanding Dipole Arrows

If a polar bond exists then dipole arrows must be used. 

Concept #3: Dipole Arrows and Bond Classifications

Depending on the difference in electronegativity, a chemical bond fits within a certain category. 

Dipole Arrow Calculations

Example #1: Based on each of the given bonds determine the direction of the dipole arrow and the polarity that may arise. 

a.  H –––– Cl

b.  S –––– O

c.  Br –––– B –––– Br

Practice: Based on the given bond determine the direction of the dipole arrow and the polarity that may arise. 

 H-C


Practice: Based on the given bond determine the direction of the dipole arrow and the polarity that may arise.

N-F

Practice: Based on the given bond determine the direction of the dipole arrow and the polarity that may arise.

H-N-H

Practice: Answer each of the following questions dealing with the following compounds.

a) Which of the following compound(s) contains a polar covalent bond?

b) Which of the following compound(s) contains a pure covalent bond?

c) Which of the following compound(s) contains a polar ionic bond?

d) Which of the following compound(s) contains both a polar ionic bond and a polar covalent bond?


Additional Problems
Magnitude of Dipole moment is dependent on the difference in electronegativity.   Arrange the following in order of increasing dipole moment:  Si—O, C—Br, Br—I.  
You may want to reference (Pages 352 - 354) Section 9.3 while completing this problem.Does the molecule BF2Cl have a dipole moment?
You may want to reference (Pages 309 - 315)Section 8.4 while completing this problem.Calculate the dipole moment for HF (bond length 0.917 Å), assuming that the bond is completely ionic.
There are two compounds of the formula Pt(NH3 )2 Cl2 as shown below. The compound on the right is called cisplatin, and the compound on the left is called transplatin. You may want to reference (Pages 338 - 393) Chapter 9 while completing this problem.Which compound has a nonzero dipole moment?
Using these partial charges and the atomic radii given in the figure , estimate the dipole moment of the molecule.
Charge separation in the hydrogen halides. In HF, the strongly electronegative F pulls much of the electron density away from H. In HI, the I, being much less electronegative than F, does not attract the shared electrons as strongly and, consequently, there is far less polarization of the bond.How do you interpret the fact that there is no red in the HBr and HI representations?
Chlorine monofluoride, ClF, and iodine monofluoride, IF, are interhalogen compounds – compounds that contain bonds between different halogen elements.Which of these molecules has the larger dipole moment?
The bond between carbon and hydrogen is one of the most important types of bonds in chemistry. The length of a H-C bond is approximately 1.1.Based on this distance and differences in electronegativity, do you expect the dipole moment of an individual H-C bond to be larger or smaller than that of the H-I bond?
The O-H bond lengths in the water molecule (H2 O) are 0.96 Å, and the H-O-H angle is 104.5 . The dipole moment of the water molecule is 1.85 D. Compound Electronegativity Difference Dipole Moment (D) HCl 1.9 1.82 HBr 0.9 1.08 HI 0.7 0.82 { m HI} 0.4 0.44 Calculate the magnitude of the bond dipole of the O-H bonds. (Note: You will need to use vector addition to do this.)
The O-H bond lengths in the water molecule (H2 O) are 0.96 Å, and the H-O-H angle is 104.5 . The dipole moment of the water molecule is 1.85 D. Compound Electronegativity Difference Dipole Moment (D) HCl 1.9 1.82 HBr 0.9 1.08 HI 0.7 0.82 { m HI} 0.4 0.44 Compare your answer from part B to the dipole moments of the hydrogen halides (the table). Is your answer in accord with the relative electronegativity of oxygen?
The HCl(g) molecule has a bond length of 127 pm and a dipole moment of 1.08 D.Without doing detailed calculations, determine the best estimate for its percent ionic character.
What is a dipole moment?
It turns out that ozone, O3, has a small dipole moment. How is this possible, given that all the atoms are the same?
Ammonia reacts with boron trifluoride to form a stable compound.The B-N bond is obviously more polar than the C-C bond. Draw the charge distribution you expect on the B-N bond within the molecule (using delta plus and delta minus symbols).
In the molecule FBr, which atom is the negative pole? 
Both of the carbon-oxygen double bonds in CO 2 are polar. In which direction should the polarity arrows point? a. Rightb. Leftc. Toward the central carbon atomd. Away from central carbon atom
Li-H molecules have the observed dipole moment of μ=6.002 D. The bond length of a Li-H bond is 0.1595 nm. Estimate the percent ionic character of Li-H bond.
Which molecule should have higher dipole moment, and why?
Which molecule below has the largest dipole moment?a. HBrb. HIc. HFd. HCle. H2
Of the molecules SiF4 and SiBr4, which has bonds that are more polar?
Place the following in order of decreasing dipole moment.I. cis-CHCl=CHCl     II. trans-CHCl=CHCl     III. cis-CHF=CHFA. II > III > I    B) III > I > II    C) I = III > II    D) II > I > III    E) I > III > II
Place the following in order of decreasing dipole moment.I. cis-CHCl=CHClII. trans-CHCl=CHCIIII. cis-CHF=CHF A) III > I > IIB) II > I > IIIC) I > III > IID) II > III > IE) I = III > II
Choose the compound below that contains at least one polar covalent bond, but is nonpolar.a. SeBr4b. HCNc. ICl3d. CF4e. Both B and C are nonpolar and contain a polar covalent bond.
Place the following in order of increasing dipole moment.I. BCl3 II. BBrF2 III. BClF2 A) I < II = IIIB) II < III < IC) I < II < IIID) II < I < IIIE) I < III < II
Which of the following DOES NOT have a dipole moment?a) COb) NCl3c) HCld) SF4e) BCl3
Two different compounds have the formula XeF2Cl2. Write Lewis structures for these two compounds, and describe how measurement of dipole moments might be used to distinguish between them.
Which atoms can bond to sulfur so as to produce a positive partial charge on the sulfur atom?
Which of the following incorrectly shows the bond polarity? Show the correct bond polarity for those that are incorrect.a. 8+H—F8-  b. 8+Cl—I8- c. 8+Si—S8-d. 8+Br—Br8-e. 8+O—P8-
State whether or not the following has a permanent dipole moment.
State whether or not the following has a permanent dipole moment.
State whether or not the following has a permanent dipole moment.
Does of the following ion contain polar bonds? Does it have dipole moments?(b) ClO2−
State whether or not the following has a permanent dipole moment.
State whether or not the following has a permanent dipole moment.
Does of the following ion contain polar bonds? Does it have dipole moments?(c) TeCl42−
State whether or not the following has a permanent dipole moment.
Does of the following molecule contain polar bonds? Does it have dipole moments?(d) PCl3
Does of the following molecule contain polar bonds? Does it have dipole moments?(e) SeF4
Does of the following ion contain polar bonds? Does it have dipole moments?(f) PH2–
Does of the following molecule contain polar bonds? Does it have dipole moments?(g) XeF2
Which of these molecules and ions contain polar bonds? Which of these molecules and ions have dipole moments?(a) H3O+(b) PCl4−(c) SnCl3−(d) BrCl4−(e) ICl3(f) XeF4(g) SF2
Which of the following molecules have dipole moments?(a) CS2(b) SeS2(c) CCl2F2(d) PCl3 (P is the central atom)(e) ClNO (N is the central atom)
Identify the molecules with a dipole moment:(a) SF4(b) CF4(c) Cl2CCBr2(d) CH3Cl(e) H2CO
The molecule XF3 has a dipole moment. Is X boron or phosphorus?
The molecule XCl2 has a dipole moment. Is X beryllium or sulfur?
Indicate the bond polarity (show the partial positive and partial negative ends) in the following bond.a. C—O 
Indicate the bond polarity (show the partial positive and partial negative ends) in the following bond.b. P—H
Indicate the bond polarity (show the partial positive and partial negative ends) in the following bond.c. H—Cl
Indicate the bond polarity (show the partial positive and partial negative ends) in the following bond.d. Br—Te
Indicate the bond polarity (show the partial positive and partial negative ends) in the following bond.e. Se—S
Use the Figure to indicate the polarity of the following bond with a polar arrow:(a) N—B
Use the Figure to indicate the polarity of the following bond with a polar arrow:(b) N—O
Use the Figure to indicate the polarity of the following bond with a polar arrow:(c) C—S
Use the Figure to indicate the polarity of the following bond with a polar arrow:(d) S—O
Use the Figure to indicate the polarity of the following bond with a polar arrow:(e) N—H
Use the Figure to indicate the polarity of the following bond with a polar arrow:(f) Cl—O
Use the Figure to indicate the polarity of following bond with partial charges:(a) Br—Cl
Use the Figure to indicate the polarity of following bond with partial charges:(b) F—Cl
Use the Figure to indicate the polarity of following bond with partial charges:(c) H—O
Use the Figure to indicate the polarity of following bond with partial charges:(d) Se—H
Use the Figure to indicate the polarity of following bond with partial charges:(e) As—H
Use the Figure to indicate the polarity of following bond with partial charges:(f) S—N
Rank the members of the following set of compounds in order of increasing ionic character of their bonds. Use polar arrows to indicate the bond polarity of each:(a) HBr, HCl, HI
Rank the members of the following set of compounds in order of increasing ionic character of their bonds. Use polar arrows to indicate the bond polarity of each:(b) H2O, CH4, HF
Rank the members of the following set of compounds in order of increasing ionic character of their bonds. Use polar arrows to indicate the bond polarity of each:(c) SCl2, PCl3, SiCl4
Rank the members of the following set of compounds in order of decreasing ionic character of their bonds. Use partial charges to indicate the bond polarity of each:(a) PCl3, PBr3, PF3
Rank the members of the following set of compounds in order of decreasing ionic character of their bonds. Use partial charges to indicate the bond polarity of each:(b) BF3, NF3, CF4
Rank the members of the following set of compounds in order of decreasing ionic character of their bonds. Use partial charges to indicate the bond polarity of each:(c) SeF4, TeF4, BrF3
Of the molecules AlCl3 and AlBr3, which has bonds that are more polar? a. AlCl3 b. AlBr3
Choose the bond below that is most polar. a. H-I b. H-Br c. H-F d. H-Cl e. C-H
If the atoms that share electrons have an unequal attraction for the electrons, the bond is called?a. nonpolarb. polarc. ionic
Which of the following bonds would you expect to be the most polar?a. P-Sb. C-Nc. O-Fd. N-Oe. C-O
The B-F bond in BF3 (electronegativity for B is 2.0, electronegativity for F is 4.0) isa. polar covalentb. ionicc. pure covalent
Which of the following molecules does not have a permanent dipole moment?a. water, H2Ob. acetone, CH3COCH3c. carbon dioxide, CO2d. sulfur dioxide, SO2e. chloromethane, CH3CI
The greater the electronegativity difference between two bonded atoms, the greater the percentage of?a. ionic characterb. metallic characterc. electron sharing
For each compound below, click in the box to toggle the direction of bond polarity (leave the nonpolar bond).
Classify the C-Cl bond in CCl 4 as ionic, polar covalent, or nonpolar covalent.a. nonpolar covalent b. ionic c. polar covalent
Why don't all molecules with polar bonds have a net dipole? 
From the compounds listed below, choose all of the compounds that contain polar covalent bonds. (i) A (ii) B (iii) C (iv) D (v) E
If a molecule has a symmetrical arrangement of polar bonds, then that mlecule isa. nonpolarb. somewhat polarc. reverse polard. highly polar 
Which of the following substances hasa zero dipole moment? Select one: a. All have zero dipole moments b. HCl2CCHCl2 c. HOCH2CH2OH d. CO2e. CI2C=CCl2
Choose the correct polarity of the bonds within SO2