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Ch.22 - The Main Group Elements
Chapter 22, Problem 152

Write an electron-dot structure for each of the following molecules or ions and predict the geometrical structure: (a) HIO3 (b) ClO2- (c) HOCl (d) IO6^5-

Verified step by step guidance
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Step 1: Determine the total number of valence electrons for each molecule or ion. For example, for HIO3, sum the valence electrons of H, I, and O atoms.
Step 2: Draw the skeletal structure of the molecule or ion, connecting atoms with single bonds. Typically, the least electronegative atom is the central atom, except for hydrogen.
Step 3: Distribute the remaining valence electrons as lone pairs to satisfy the octet rule for each atom, starting with the outer atoms. Adjust for any charges in ions.
Step 4: If any atoms lack an octet, consider forming double or triple bonds by converting lone pairs from adjacent atoms into bonding pairs.
Step 5: Use VSEPR theory to predict the molecular geometry based on the electron-pair arrangement around the central atom, considering both bonding and lone pairs.

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Electron-Dot Structures (Lewis Structures)

Electron-dot structures, or Lewis structures, represent the valence electrons of atoms within a molecule. They illustrate how atoms are bonded together and show lone pairs of electrons. By following the octet rule, these structures help predict the arrangement of electrons and the connectivity between atoms, which is essential for understanding molecular geometry.
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VSEPR Theory

Valence Shell Electron Pair Repulsion (VSEPR) theory is a model used to predict the geometry of molecules based on the repulsion between electron pairs around a central atom. According to VSEPR, electron pairs, whether bonding or lone pairs, will arrange themselves to minimize repulsion, leading to specific molecular shapes such as linear, trigonal planar, or tetrahedral.
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Formal Charge

Formal charge is a concept used to determine the distribution of electrons in a molecule and assess the stability of a Lewis structure. It is calculated by comparing the number of valence electrons in the free atom to the number of electrons assigned to it in the structure. A lower formal charge on atoms generally indicates a more stable structure, guiding the drawing of accurate electron-dot representations.
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