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Ch.6 Ionic and Molecular Compounds
Timberlake - Chemistry: An Introduction to General, Organic, and Biological Chemistry 13th Edition
Timberlake13th EditionChemistry: An Introduction to General, Organic, and Biological ChemistryISBN: 9780134421353Not the one you use?Change textbook
Chapter 6, Problem 28a

Write the symbol for the cation in each of the following ionic compounds:
a. FeCl2

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1
Identify the chemical formula of the compound: FeCl₂. This indicates that the compound contains iron (Fe) and chloride (Cl) ions.
Determine the charge of the chloride ion (Cl⁻). Chloride is a halogen and typically forms a -1 charge as an anion.
Since there are two chloride ions in FeCl₂, the total negative charge contributed by the chloride ions is -2 (2 × -1 = -2).
To balance the overall charge of the compound (which must be neutral), the iron (Fe) cation must have a charge of +2 to counteract the -2 charge from the chloride ions.
Write the symbol for the cation, including its charge: Fe²⁺.

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Key Concepts

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

Ionic Compounds

Ionic compounds are formed when atoms transfer electrons, resulting in the formation of charged ions. Typically, a metal atom loses electrons to become a positively charged cation, while a non-metal atom gains electrons to become a negatively charged anion. The electrostatic attraction between these oppositely charged ions holds the compound together.
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Cations and Anions

Cations are positively charged ions that result from the loss of one or more electrons, while anions are negatively charged ions formed by the gain of electrons. In ionic compounds, cations are usually metals, and anions are non-metals or polyatomic ions. Understanding the charge and identity of these ions is crucial for writing the correct formulas and symbols for ionic compounds.
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Oxidation States

Oxidation states indicate the degree of oxidation of an atom in a compound, reflecting the number of electrons lost or gained. In the case of FeCl₂, iron (Fe) can have multiple oxidation states, but in this compound, it has an oxidation state of +2. Recognizing the oxidation state helps in determining the correct symbol for the cation, which in this case is Fe²⁺.
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