How does the written Lewis structure for lithium iodide differ from that of hydrogen iodide? Explain why they appear different in terms of bonding.
F. Construct the Lewis structure model for the covalent compound carbon tetrafluoride, CF4.
G. Construct the Lewis structure model for the covalent compound ammonia, NH3.
H. Construct the Lewis structure model for the covalent compound carbon dioxide, CO.
I. Construct the Lewis structure model for the covalent compound sulfur hexafluoride, SF. Why can this compound be formed using S but not as the central atom?
J. Construct the Lewis structure model for the covalent compound methylene chloride (CH2Cl2). Is there more than one three-dimensional structure for this molecule? Build the molecule with the molecule kit and explain whether or not more than one three- dimensional structure is possible.
The Correct Answer and Explanation is :
A. Lewis Structure Differences Between Lithium Iodide (LiI) and Hydrogen Iodide (HI)
The Lewis structure for lithium iodide (LiI) is very different from hydrogen iodide (HI) because of the types of bonding involved.
- Lithium iodide (LiI): Lithium (Li) is a metal and iodine (I) is a non-metal. Lithium tends to lose one electron to form a cation (Li⁺), while iodine accepts an electron to become an anion (I⁻). This results in an ionic bond. In the Lewis structure, lithium will be represented with no valence electrons, and iodine will have a full octet of electrons. The bond between them is represented by an arrow from Li⁺ to I⁻ to show electron transfer.
- Hydrogen iodide (HI): In hydrogen iodide, both hydrogen (H) and iodine (I) are non-metals, so they share electrons to form a covalent bond. The hydrogen atom shares its single electron with iodine, which has seven valence electrons, forming a shared electron pair to complete its octet. The Lewis structure for HI involves a single bond (line) between H and I, with iodine having three lone pairs of electrons.
B. Lewis Structure of Carbon Tetrafluoride (CF₄)
In CF₄, carbon is the central atom. Carbon has 4 valence electrons, and each fluorine atom (F) has 7 valence electrons. The carbon atom will form four single bonds with four fluorine atoms, sharing one electron with each fluorine. Each fluorine will have three lone pairs of electrons. The structure is tetrahedral.
C. Lewis Structure of Ammonia (NH₃)
In NH₃, nitrogen is the central atom. Nitrogen has 5 valence electrons, and hydrogen has 1 valence electron. Nitrogen will form three single bonds with hydrogen atoms, sharing one electron with each hydrogen. Nitrogen will also have one lone pair of electrons. The structure is trigonal pyramidal.
D. Lewis Structure of Carbon Dioxide (CO₂)
In CO₂, carbon is the central atom. Carbon has 4 valence electrons, and oxygen has 6 valence electrons. Carbon forms two double bonds with two oxygen atoms, sharing four electrons in each bond. Each oxygen atom has two lone pairs of electrons. The structure is linear.
E. Lewis Structure of Sulfur Hexafluoride (SF₆)
In SF₆, sulfur is the central atom. Sulfur has 6 valence electrons, and fluorine has 7 valence electrons. Sulfur can form six bonds with six fluorine atoms, each sharing one electron with sulfur. The structure is octahedral. Sulfur can form this structure because it can accommodate more than eight electrons in its valence shell due to its position in period 3 of the periodic table.
F. Lewis Structure of Methylene Chloride (CH₂Cl₂)
In CH₂Cl₂, carbon is the central atom, with two hydrogens and two chlorine atoms attached. Carbon has 4 valence electrons, hydrogen has 1 valence electron, and chlorine has 7 valence electrons. Carbon forms two single bonds with hydrogen atoms and two single bonds with chlorine atoms. Each chlorine atom has three lone pairs of electrons. The structure is tetrahedral, and there is only one possible three-dimensional structure because the atoms are arranged symmetrically around the carbon.
Image Generation
I will now generate a visual representation of the molecule.
Here is a visual representation of the Lewis structures for several molecules including lithium iodide (LiI), hydrogen iodide (HI), carbon tetrafluoride (CF₄), ammonia (NH₃), carbon dioxide (CO₂), sulfur hexafluoride (SF₆), and methylene chloride (CH₂Cl₂). The diagram highlights their bonding arrangements and molecular shapes.
