Determine the polarity (polar or nonpolar) and the type of intermolecular forces of attraction (IMFA) for the following compounds:
| Compound | Polarity (Polar or Nonpolar) | Type of IMFA |
|---|---|---|
| H₂O (water) | polar | H-bonding |
| XeF₄ (xenon tetrafluoride) | | |
| Acetone | | |
| O₃ (ozone) | | |
| SF₆ (sulfur hexafluoride) | | |
| H-C≡N: (hydrogen cyanide) | | |
Molecular structures:
Water: H-O-H
Acetone: H-C-C-C-H
Ozone: O=O-O
Xenon tetrafluoride: F-Xe-F
|
F
|
F
Sulfur hexafluoride: F-S-F
|
F
|
F
Hydrogen cyanide: H-C≡N
Answer (2)
To determine the polarity and intermolecular forces of attraction (IMFA) for the given compounds, we need to look at their molecular structure and the difference in electronegativity between the atoms involved:
H₂O (Water):
Polarity: Polar
Type of IMFA: Hydrogen bonding. Water is a polar molecule with a bent shape, which leads to a high electronegativity difference between oxygen and hydrogen, causing strong hydrogen bonding.
XeF₄ (Xenon Tetrafluoride):
Polarity: Nonpolar
Type of IMFA: London dispersion forces. Despite being made of highly electronegative fluorine atoms, the symmetric square planar shape cancels out the dipoles, making XeF₄ nonpolar.
Acetone (C₃H₆O):
Polarity: Polar
Type of IMFA: Dipole-dipole interactions. Acetone has a polar carbonyl group (C=O), which results in a dipole moment. It can also temporarily participate in hydrogen bonding due to the carbonyl oxygen.
O₃ (Ozone):
Polarity: Polar
Type of IMFA: Dipole-dipole interactions. Ozone has a bent shape and an uneven distribution of charge, leading to a polar character.
SF₆ (Sulfur Hexafluoride):
Polarity: Nonpolar
Type of IMFA: London dispersion forces. The octahedral geometry of SF₆ makes it symmetrically balanced, leading to a nonpolar molecule.
H-C≡N: (Hydrogen Cyanide):
Polarity: Polar
Type of IMFA: Dipole-dipole interactions. Hydrogen cyanide is a linear but polar molecule because of the significant difference in electronegativity between hydrogen and nitrogen, and the presence of a triple bond significantly contributes to its dipole moment.
Understanding these properties helps explain how these molecules will interact with each other and their physical properties. Polarity is greatly influenced by molecular geometry and electronegativity differences, while IMFA depends on polarity and the types of atoms around the bonds.
The compounds have varying polarities and intermolecular forces. Water, for instance, is polar with hydrogen bonding, while xenon tetrafluoride is nonpolar with London dispersion forces. Understanding molecular structure and electronegativity differences is key to predicting these properties.
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