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 Globe with Meridians

Chapter 3 - Classification Of Matter

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Atom Symbol

Chapter 1 - Models Of The Particulate Nature Of Matter

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Chapter 2 - Models Of Bonding & Structure

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Fire

Chapter 4 - What Drives Chemical Reactions?

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Rocket

Chapter 5 - How Much, How Fast & How Far?

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Test Tube

Chapter 6 - What Are The Mechanisms Of Chemical Change?

<ul>
	<li>Metal Oxides and Non-metal Oxides</li>
	<li>Lewis Acid-Base Theory</li>
	<li>Acid-Base Reactions</li>
</ul>

<ul>
	<li>Metal oxides are typically formed when metals react with oxygen.</li>
	<li>Non-metal oxides are formed when non-metals react with oxygen.</li>
</ul>

<ul>
	<li>A Lewis acid can accept an electron pair, while a Lewis base can donate an electron pair.</li>
	<li>Many metal oxides are Lewis bases, while non-metallic oxides are Lewis acids.</li>
</ul>

<ul>
	<li>Metal oxides react with water to form hydroxides by donating an electron pair to hydrogen in water.</li>
	<li>Alkali metal oxides (Group 1 elements) react with water according to the equation: M2O(s) + H2O(l) &rarr; 2MOH(aq).
	<ul>
		<li>For example, sodium oxide reacts with water to form sodium hydroxide: Na2O(s) + H2O(l) &rarr; 2NaOH(aq).</li>
		<li>Likewise, lithium oxide reacts with water to form lithium hydroxide: Li2O(s) + H2O(l) &rarr; 2LiOH(aq).</li>
	</ul>
	</li>
	<li>Group 2 oxides react with water according to the equation: MO(s) + H2O(l) &rarr; M(OH)2(aq).
	<ul>
		<li>For example, magnesium oxide reacts with water to form magnesium hydroxide: MgO(s) + H2O(l) &rarr; Mg(OH)2(s).</li>
		<li>Barium oxide reacts with water to form barium hydroxide: BaO(s) + H2O(l) &rarr; Ba(OH)2(aq).</li>
	</ul>
	</li>
	<li>Non-metallic oxides react with water to form other acids by accepting an electron pair from oxygen in water.
	<ul>
		<li>For example, carbon dioxide reacts with water to form carbonic acid: CO2(g) + H2O(l) &rarr; H2CO3(aq).</li>
		<li>Similarly, sulfur dioxide and sulfur trioxide react with water to form sulfurous acid and sulfuric acid, respectively.</li>
		<li>Phosphorus(V) oxide reacts with water to form phosphoric acid: P4O10(s) + 6H2O(l) &rarr; 4H3PO4(aq).</li>
	</ul>
	</li>
	<li>Going across any period, the oxides of the elements become less basic and more acidic. For instance, Na2O forms a stronger base than MgO, and SO3 forms a stronger acid than P4O10.</li>
	<li>A chemical species that behaves as both a Lewis acid and a Lewis base is termed amphoteric.
	<ul>
		<li>Aluminium oxide, Al2O3, is amphoteric; it can accept or donate an electron pair depending on what it reacts with.</li>
		<li>In reaction with sodium hydroxide, aluminium oxide acts as a Lewis acid: Al2O3 + 2NaOH + 3H2O &rarr; 2Na[Al(OH)4].</li>
		<li>In reaction with hydrochloric acid, aluminium oxide acts as a Lewis base: Al2O3 + 6HCl &rarr; 2AlCl3 + 3H2O.</li>
		<li>These reactions are neutralization reactions, where an acid and a base react to form a salt.</li>
	</ul>
	</li>
</ul>

<ul>
	<li>Carbon Dioxide and Ocean Acidification: When CO2 reacts with seawater, it forms carbonic acid, leading to ocean acidification, which affects marine life.</li>
	<li>Sulfur Dioxide and Acid Rain: Sulfur dioxide reacts with water in the atmosphere to form sulfurous acid, which can lead to acid rain and harm forests and aquatic ecosystems.</li>
	<li>Aluminium Oxide in Water Treatment: Aluminium oxide&#39;s amphoteric properties are used in water treatment to neutralize acidic or alkaline wastewater.</li>
</ul>

Metal oxides, generally basic, react with water to form hydroxides. Non-metal oxides, typically acidic, react with water to form other acids. Aluminium oxide is an example of an amphoteric oxide, which can behave as both an acid and a base. Understanding these reactions helps us understand real-world phenomena like ocean acidification and acid rain.

Chapter 3 - Classification Of Matter

Understanding Metal and Non-Metal Oxides: Key to Acids & Bases

Table of content

Key concepts

Notes & explanations

Metal oxides & non-metal oxides

Lewis acid-base theory

Unlock the Full Content!

Chapter 3 - Classification Of Matter

Understanding Metal and Non-Metal Oxides: Key to Acids & Bases

Table of content

Key concepts

Notes & explanations

Metal oxides & non-metal oxides

Lewis acid-base theory

Unlock the Full Content!