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Ch.22 - The Main Group Elements
Chapter 22, Problem 123

If an element forms an ionic hydride, is it more likely to form an acidic or basic oxide?

Verified step by step guidance
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Step 1: Understand the nature of ionic hydrides. Ionic hydrides are formed when hydrogen gains an electron from a metal, typically from Group 1 (alkali metals) or Group 2 (alkaline earth metals) elements, resulting in a hydride ion (H⁻).
Step 2: Recognize the properties of elements that form ionic hydrides. These elements are usually metals that are electropositive, meaning they tend to lose electrons easily to form positive ions.
Step 3: Consider the nature of oxides formed by these metals. Metals that form ionic hydrides are typically basic in nature, and their oxides are also basic. Basic oxides react with water to form hydroxides, which are basic in solution.
Step 4: Compare with acidic oxides. Acidic oxides are usually formed by nonmetals and react with water to form acids. Since the elements forming ionic hydrides are metals, they are less likely to form acidic oxides.
Step 5: Conclude that elements forming ionic hydrides are more likely to form basic oxides due to their metallic and electropositive nature, which leads to the formation of basic compounds when combined with oxygen.

Key Concepts

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

Ionic Hydrides

Ionic hydrides are compounds formed between metals and hydrogen, where hydrogen acts as a hydride ion (H-). These hydrides typically form with alkali and alkaline earth metals, which have low electronegativities and readily lose electrons to hydrogen. The nature of ionic hydrides suggests that the metal's properties will influence the type of oxides it forms.
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Acidic vs. Basic Oxides

Oxides can be classified as acidic, basic, or amphoteric based on their behavior in reactions with acids and bases. Basic oxides, often formed by metals, react with acids to produce salts and water, while acidic oxides, typically formed by nonmetals, react with bases. The classification is crucial for predicting the behavior of oxides formed by elements that also form ionic hydrides.
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Periodic Trends

Periodic trends refer to the predictable patterns in elemental properties across the periodic table, such as electronegativity, ionization energy, and metallic character. Elements that form ionic hydrides are usually found in the left side of the periodic table, where metallic character is high. This trend indicates that such elements are more likely to form basic oxides, as they tend to lose electrons easily and react with acids.
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