Answer :
To determine which molecule or compound exhibits dipole-dipole forces as its strongest intermolecular force, we need to carefully analyze the molecular structure and the type of intermolecular forces present in each compound. Let's examine them one by one:
1. Br[tex]\(_2\)[/tex] (Bromine):
- Molecular Structure: Br[tex]\(_2\)[/tex] is a diatomic molecule consisting of two bromine atoms.
- Polarity: Since both atoms are the same, the electron distribution is symmetrical.
- Intermolecular Forces: Nonpolar molecules like Br[tex]\(_2\)[/tex] exhibit London dispersion forces, which are relatively weak intermolecular forces caused by temporary dipoles.
2. SO[tex]\(_2\)[/tex] (Sulfur dioxide):
- Molecular Structure: SO[tex]\(_2\)[/tex] is a bent molecule with sulfur bonded to two oxygen atoms.
- Polarity: Due to its asymmetric shape and the difference in electronegativity between sulfur and oxygen, SO[tex]\(_2\)[/tex] is a polar molecule.
- Intermolecular Forces: Polar molecules exhibit dipole-dipole forces. Hence, SO[tex]\(_2\)[/tex] molecules will have significant dipole-dipole attractions.
3. H[tex]\(_2\)[/tex]O (Water):
- Molecular Structure: H[tex]\(_2\)[/tex]O has a bent shape with oxygen bonded to two hydrogen atoms.
- Polarity: Water is highly polar due to the difference in electronegativity between hydrogen and oxygen atoms.
- Intermolecular Forces: The strongest intermolecular force in water is hydrogen bonding, a special type of dipole-dipole force that occurs when hydrogen is bonded to highly electronegative atoms like oxygen.
4. CF[tex]\(_4\)[/tex] (Carbon tetrafluoride):
- Molecular Structure: CF[tex]\(_4\)[/tex] is a tetrahedral molecule with carbon bonded to four fluorine atoms.
- Polarity: The symmetry of the tetrahedral shape causes the dipoles to cancel out, resulting in a nonpolar molecule.
- Intermolecular Forces: Nonpolar molecules like CF[tex]\(_4\)[/tex] exhibit London dispersion forces.
Given this analysis:
- Br[tex]\(_2\)[/tex]: London dispersion forces
- SO[tex]\(_2\)[/tex]: Dipole-dipole forces
- H[tex]\(_2\)[/tex]O: Hydrogen bonding (a type of dipole-dipole force but stronger)
- CF[tex]\(_4\)[/tex]: London dispersion forces
Therefore, the molecule that exhibits dipole-dipole forces as its strongest intermolecular force is SO[tex]\(_2\)[/tex]*.
So, the correct answer is [tex]\( \boxed{2} \)[/tex].
1. Br[tex]\(_2\)[/tex] (Bromine):
- Molecular Structure: Br[tex]\(_2\)[/tex] is a diatomic molecule consisting of two bromine atoms.
- Polarity: Since both atoms are the same, the electron distribution is symmetrical.
- Intermolecular Forces: Nonpolar molecules like Br[tex]\(_2\)[/tex] exhibit London dispersion forces, which are relatively weak intermolecular forces caused by temporary dipoles.
2. SO[tex]\(_2\)[/tex] (Sulfur dioxide):
- Molecular Structure: SO[tex]\(_2\)[/tex] is a bent molecule with sulfur bonded to two oxygen atoms.
- Polarity: Due to its asymmetric shape and the difference in electronegativity between sulfur and oxygen, SO[tex]\(_2\)[/tex] is a polar molecule.
- Intermolecular Forces: Polar molecules exhibit dipole-dipole forces. Hence, SO[tex]\(_2\)[/tex] molecules will have significant dipole-dipole attractions.
3. H[tex]\(_2\)[/tex]O (Water):
- Molecular Structure: H[tex]\(_2\)[/tex]O has a bent shape with oxygen bonded to two hydrogen atoms.
- Polarity: Water is highly polar due to the difference in electronegativity between hydrogen and oxygen atoms.
- Intermolecular Forces: The strongest intermolecular force in water is hydrogen bonding, a special type of dipole-dipole force that occurs when hydrogen is bonded to highly electronegative atoms like oxygen.
4. CF[tex]\(_4\)[/tex] (Carbon tetrafluoride):
- Molecular Structure: CF[tex]\(_4\)[/tex] is a tetrahedral molecule with carbon bonded to four fluorine atoms.
- Polarity: The symmetry of the tetrahedral shape causes the dipoles to cancel out, resulting in a nonpolar molecule.
- Intermolecular Forces: Nonpolar molecules like CF[tex]\(_4\)[/tex] exhibit London dispersion forces.
Given this analysis:
- Br[tex]\(_2\)[/tex]: London dispersion forces
- SO[tex]\(_2\)[/tex]: Dipole-dipole forces
- H[tex]\(_2\)[/tex]O: Hydrogen bonding (a type of dipole-dipole force but stronger)
- CF[tex]\(_4\)[/tex]: London dispersion forces
Therefore, the molecule that exhibits dipole-dipole forces as its strongest intermolecular force is SO[tex]\(_2\)[/tex]*.
So, the correct answer is [tex]\( \boxed{2} \)[/tex].
