Table of contents

1. Intro to General Chemistry3h 48m
2. Atoms & Elements4h 16m
3. Chemical Reactions4h 10m
4. BONUS: Lab Techniques and Procedures1h 38m
5. BONUS: Mathematical Operations and Functions48m
6. Chemical Quantities & Aqueous Reactions3h 53m
7. Gases3h 49m
8. Thermochemistry2h 37m
9. Quantum Mechanics2h 58m
10. Periodic Properties of the Elements3h 9m
11. Bonding & Molecular Structure3h 29m
12. Molecular Shapes & Valence Bond Theory1h 57m
13. Liquids, Solids & Intermolecular Forces2h 23m
14. Solutions3h 1m
15. Chemical Kinetics2h 53m
16. Chemical Equilibrium2h 29m
17. Acid and Base Equilibrium5h 1m
18. Aqueous Equilibrium4h 47m
19. Chemical Thermodynamics1h 50m
20. Electrochemistry2h 42m
21. Nuclear Chemistry2h 36m
22. Organic Chemistry5h 7m
23. Chemistry of the Nonmetals2h 39m
24. Transition Metals and Coordination Compounds3h 16m

13. Liquids, Solids & Intermolecular Forces

Molecular Polarity

General Chemistry

13. Liquids, Solids & Intermolecular Forces

Molecular Polarity

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Multiple Choice

Which one of the following molecules is polar?

NH_3

CO_2

CCl_4

BF_3

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Verified step by step guidance

Step 1: Understand that molecular polarity depends on both the polarity of individual bonds and the geometry of the molecule. A molecule is polar if it has a net dipole moment, meaning the bond dipoles do not cancel out.

Step 2: Analyze the molecular geometry of each molecule using VSEPR theory: CO_2 is linear, CCl_4 is tetrahedral, BF_3 is trigonal planar, and NH_3 is trigonal pyramidal.

Step 3: Consider the electronegativity differences and bond dipoles. For example, in CO_2, the C=O bonds are polar, but because the molecule is linear and symmetrical, the dipoles cancel out, making it nonpolar.

Step 4: Evaluate the symmetry and dipole cancellation in each molecule. CCl_4 is symmetrical tetrahedral with identical C-Cl bonds, so dipoles cancel. BF_3 is trigonal planar and symmetrical, so dipoles cancel as well.

Step 5: Recognize that NH_3 has a trigonal pyramidal shape with a lone pair on nitrogen, causing an asymmetrical distribution of charge. This results in a net dipole moment, making NH_3 polar.