Determine the molecular geometry for the following molecule: IF₄^–.

• A. Square planar
• B. Square pyramidal
• C. Trigonal bipyramidal
• D. Seesaw

Answer: (A)

Verified step by step guidance

1. Determine the total number of valence electrons for the molecule IF\_4\(\textsuperscript{–}\). Iodine (I) has 7 valence electrons, each fluorine (F) has 7 valence electrons, and the negative charge adds 1 extra electron. Calculate the total as: \(7 + 4 \times 7 + 1\).
2. Draw the Lewis structure by placing iodine as the central atom and connecting it to four fluorine atoms with single bonds. Then, distribute the remaining electrons to satisfy the octet rule for fluorine atoms and place any leftover electrons on the central iodine atom as lone pairs.
3. Count the number of bonding pairs and lone pairs around the central iodine atom. This will help determine the electron pair geometry using the VSEPR (Valence Shell Electron Pair Repulsion) theory.
4. Use the VSEPR model to predict the molecular geometry. For example, if there are 4 bonding pairs and 2 lone pairs around iodine, the electron pair geometry is octahedral, but the molecular shape is determined by the positions of atoms only, which leads to a square planar shape.
5. Compare the predicted molecular geometry with the given options: square planar, square pyramidal, trigonal bipyramidal, and seesaw. Identify which geometry corresponds to the arrangement of atoms and lone pairs you found.