Draw the Lewis structure for each compound. b. H₃PO₃ (two OH bonds)

Verified step by step guidance

1. Count the total number of valence electrons in the molecule. Phosphorus (P) has 5 valence electrons, each hydrogen (H) has 1, and each oxygen (O) has 6. Since there are three hydrogens and three oxygens, the total number of valence electrons is 5 (from P) + 3 (from H) + 18 (from O) = 26 valence electrons.
2. Place the least electronegative atom in the center, which is phosphorus in this case. Then, attach the oxygen and hydrogen atoms to the central phosphorus atom. Remember that two of the oxygens are bonded to hydrogen as OH groups.
3. Distribute the electrons around the atoms to complete the octets (or duet for hydrogen) while keeping in mind the total number of valence electrons. Each hydrogen will share two electrons, forming a single bond with oxygen. Each oxygen in the OH groups will form a single bond with hydrogen and a single bond with phosphorus.
4. Place any remaining electrons on the oxygen atoms to complete their octets. Oxygen typically needs 8 electrons to complete its octet, which includes shared and lone pairs.
5. Check the formal charges on each atom to ensure the most stable structure. The sum of the formal charges should equal the overall charge of the molecule, which is neutral in this case.

Key Concepts

Lewis Structures

Lewis structures are diagrams that represent the bonding between atoms in a molecule and the lone pairs of electrons that may exist. They use dots to represent valence electrons and lines to represent bonds between atoms. Understanding how to draw Lewis structures is essential for visualizing molecular geometry and predicting the behavior of molecules in chemical reactions.

Valence Electrons

Valence electrons are the outermost electrons of an atom and are crucial in determining how an atom bonds with others. The number of valence electrons influences the atom's ability to form bonds, either by sharing electrons (covalent bonds) or transferring them (ionic bonds). For H3PO3, knowing the valence electrons of hydrogen, phosphorus, and oxygen is key to constructing its Lewis structure accurately.

Molecular Geometry

Molecular geometry refers to the three-dimensional arrangement of atoms within a molecule. It is influenced by the number of bonds and lone pairs around the central atom, which can affect the molecule's reactivity and properties. In the case of H3PO3, understanding its geometry helps predict how it interacts with other molecules and its overall stability.