Given a list of compounds, show the following:
a) General Formula, i.e., AX3E;
b) Lewis structure;
c) Name of molecular shape;
d) Polarity of molecule (For example, is it polar or nonpolar?)
NF3, XeCl4, SF6, PBr5, F2O, BCI3, SiO2, XeF2, PH3, N2
The Correct Answer and Explanation is :
Here’s a breakdown of the compounds listed, including their general formulas, Lewis structures, molecular shapes, and polarity:
1. NF3 (Nitrogen trifluoride)
- General Formula: AX3E
- Lewis Structure: Nitrogen (N) is bonded to three fluorine (F) atoms, with one lone pair on nitrogen.
- Molecular Shape: Trigonal pyramidal
- Polarity: Polar
- Explanation: The presence of a lone pair on nitrogen creates an asymmetrical shape, and because fluorine is more electronegative than nitrogen, there is a dipole moment.
2. XeCl4 (Xenon tetrachloride)
- General Formula: AX4E2
- Lewis Structure: Xenon (Xe) is bonded to four chlorine (Cl) atoms, with two lone pairs on xenon.
- Molecular Shape: Square planar
- Polarity: Nonpolar
- Explanation: The symmetrical arrangement of chlorine atoms around xenon results in a nonpolar molecule.
3. SF6 (Sulfur hexafluoride)
- General Formula: AX6
- Lewis Structure: Sulfur (S) is bonded to six fluorine (F) atoms, with no lone pairs on sulfur.
- Molecular Shape: Octahedral
- Polarity: Nonpolar
- Explanation: The symmetrical geometry results in no dipole moment, making it nonpolar.
4. PBr5 (Phosphorus pentabromide)
- General Formula: AX5
- Lewis Structure: Phosphorus (P) is bonded to five bromine (Br) atoms, with no lone pairs on phosphorus.
- Molecular Shape: Trigonal bipyramidal
- Polarity: Nonpolar
- Explanation: The symmetrical geometry of the molecule results in no dipole moment.
5. F2O (Difluorine monoxide)
- General Formula: AX2E2
- Lewis Structure: Oxygen (O) is bonded to two fluorine (F) atoms, with two lone pairs on oxygen.
- Molecular Shape: Bent
- Polarity: Polar
- Explanation: The bent shape causes a net dipole moment due to the electronegativity difference between fluorine and oxygen.
6. BCl3 (Boron trichloride)
- General Formula: AX3
- Lewis Structure: Boron (B) is bonded to three chlorine (Cl) atoms, with no lone pairs on boron.
- Molecular Shape: Trigonal planar
- Polarity: Nonpolar
- Explanation: The molecule is symmetrical, so there is no dipole moment, making it nonpolar.
7. SiO2 (Silicon dioxide)
- General Formula: AX2 (for each SiO2 unit)
- Lewis Structure: Silicon (Si) is bonded to two oxygen (O) atoms, forming a network structure.
- Molecular Shape: Linear (for individual SiO2 units), but it forms a giant covalent structure.
- Polarity: Nonpolar
- Explanation: In the solid structure, the molecule’s symmetry and the network of covalent bonds result in a nonpolar nature.
8. XeF2 (Xenon difluoride)
- General Formula: AX2E3
- Lewis Structure: Xenon (Xe) is bonded to two fluorine (F) atoms, with three lone pairs on xenon.
- Molecular Shape: Linear
- Polarity: Nonpolar
- Explanation: The symmetrical arrangement of fluorine atoms around xenon makes the molecule nonpolar.
9. PH3 (Phosphine)
- General Formula: AX3E
- Lewis Structure: Phosphorus (P) is bonded to three hydrogen (H) atoms, with one lone pair on phosphorus.
- Molecular Shape: Trigonal pyramidal
- Polarity: Polar
- Explanation: The lone pair on phosphorus causes an asymmetrical shape, leading to a net dipole moment.
10. N2 (Nitrogen)
- General Formula: AX
- Lewis Structure: Two nitrogen (N) atoms are triple-bonded, with each nitrogen having one lone pair.
- Molecular Shape: Linear
- Polarity: Nonpolar
- Explanation: Since both nitrogen atoms have the same electronegativity, there is no dipole moment, making the molecule nonpolar.
Summary of Molecular Shapes:
- Trigonal pyramidal: NF3, PH3
- Square planar: XeCl4
- Octahedral: SF6
- Trigonal bipyramidal: PBr5
- Bent: F2O
- Trigonal planar: BCl3
- Linear: XeF2, N2
The polarity of each molecule depends on its molecular geometry and the difference in electronegativity between the atoms involved.