Ch.22 - Chemistry of the Nonmetals
Chapter 22, Problem 52
Complete the exercises below. Write the Lewis structure for each of the following species, describe its geometry, and indicate the oxidation state of the nitrogen: a. NH₄⁺, b. NO₂⁻, c. N₂O, d. NO₂.
Verified step by step guidance1
Step 1: For each species, determine the total number of valence electrons. For NH₄⁺, count the valence electrons from nitrogen and hydrogen, and adjust for the positive charge. For NO₂⁻, count the valence electrons from nitrogen and oxygen, and adjust for the negative charge. For N₂O, count the valence electrons from both nitrogen atoms and oxygen. For NO₂, count the valence electrons from nitrogen and oxygen.
Step 2: Draw the Lewis structure for each species. Start by placing the least electronegative atom in the center (except for hydrogen, which is always terminal). Distribute the electrons to satisfy the octet rule for each atom, using double or triple bonds if necessary.
Step 3: Describe the geometry of each species using VSEPR theory. For NH₄⁺, consider the electron pair geometry around the central nitrogen atom. For NO₂⁻ and NO₂, consider the arrangement of atoms and lone pairs around the nitrogen atom. For N₂O, consider the linear arrangement of atoms.
Step 4: Determine the oxidation state of nitrogen in each species. Assign oxidation states based on the typical oxidation states of hydrogen and oxygen, and use the overall charge of the species to solve for the oxidation state of nitrogen.
Step 5: Review the Lewis structures, geometries, and oxidation states to ensure they are consistent with known chemical principles and the given charges of the species.
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
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 help visualize the arrangement of electrons and the connectivity of atoms, which is essential for predicting molecular geometry and reactivity. Understanding how to draw Lewis structures involves knowing the total number of valence electrons and how they are distributed among the atoms.
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Molecular Geometry
Molecular geometry refers to the three-dimensional arrangement of atoms within a molecule. It is determined by the number of bonding pairs and lone pairs of electrons around the central atom, which influences the shape of the molecule. Common geometries include linear, trigonal planar, tetrahedral, and bent, and they can be predicted using the VSEPR (Valence Shell Electron Pair Repulsion) theory.
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Oxidation States
Oxidation states (or oxidation numbers) indicate the degree of oxidation of an atom in a compound, reflecting the number of electrons lost or gained. They are useful for understanding redox reactions and the distribution of electrons in molecules. The oxidation state of nitrogen can vary widely, and determining it involves analyzing the bonding and the overall charge of the species, which is crucial for understanding its chemical behavior.
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