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Ch.13 - Solids & Modern Materials
Chapter 13, Problem 58

What is the oxidation state of each element in the compound Mg3Si2O5(OH)4 formed by replacing aluminum ions in kaolinite with magnesium ions?

Verified step by step guidance
1
Identify the oxidation state of oxygen (O) in compounds, which is typically -2.
Recognize that hydrogen (H) in hydroxide (OH) usually has an oxidation state of +1.
Assign the oxidation state of magnesium (Mg) as +2, which is common for alkaline earth metals.
Let the oxidation state of silicon (Si) be x. Set up the equation based on the compound's neutrality: 3(+2) + 2(x) + 5(-2) + 4(+1) = 0.
Solve the equation for x to find the oxidation state of silicon.

Key Concepts

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

Oxidation State

The oxidation state, or oxidation number, is a value that represents the total number of electrons an atom either gains or loses when it forms a compound. It helps in understanding the electron transfer in redox reactions and is crucial for determining the reactivity and stability of compounds. Oxidation states are assigned based on a set of rules, including the fact that the oxidation state of an element in its elemental form is zero.
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Ionic Compounds

Ionic compounds are formed when atoms transfer electrons, resulting in the formation of positively charged cations and negatively charged anions. In the context of the compound Mg3Si2O5(OH)4, magnesium acts as a cation, while silicon and oxygen contribute to the anionic part. Understanding the nature of ionic bonding is essential for determining the oxidation states of the elements involved.
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Polyatomic Ions

Polyatomic ions are ions composed of two or more atoms that are covalently bonded together and carry a net charge. In the compound Mg3Si2O5(OH)4, the hydroxide ion (OH) is a common polyatomic ion. Recognizing the presence and charge of polyatomic ions is important for calculating the overall charge balance in a compound and for determining the oxidation states of the individual elements.
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