Chapter 8 - Acids and Bases and Oxidation-Reduction

Chapter 8 - Acids and Bases and Oxidation-Reduction




↑ Chapter 8 - Acids and Bases and Oxidation-Reduction

8.1 - Acids and Bases

Acids: T aste sour, dissolve some metals, cause plant dye to change color

Bases: Taste bitter, are slippery, are corrosive




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, Two theories that help us to understand the chemistry of acids and bases

Arrhenius Theory

Acid: A substance, when dissolved in water, dissociates to produce hydrogen ions
(protons)

Like HCl

HCl( ) H+ ( ) +Cl− ( )




Base: A substance, when dissolved in water, dissociates to produce hydroxide ions

Like NaOH

NaOH( ) Na+ ( ) + OH− ( )




Though Arrhenius's theory does not work on all compounds

For example NH3 is a base but it does not release



Brønsted-Lowry Theory

Acid: Proton (H+ ) donor

Base: Proton (H+ ) acceptor

Notice that acid and base are not defined using water

When writing the reactions, both accepting and donation are evident



HCl( ) + H2O( ) → Cl− ( ) + H 3O + ( )

HCl is an acid because it donated a proton

H2O is a base because it accepted a proton



NH3( ) + H2O( ) NH4+ ( ) + OH − ( )

H2O is an acid because it donated a proton

NH3 is a base because it accepted a proton




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