Transcript Acids, Bases, and Salts

Acids, Bases, and
Salts
Chapter 19.1
• Leah sure is sick. The doctor said she can not eat
anything acidic. It will make her stomach hurt
really bad.
• How can she tell if she should eat a certain food
or not based on its acidity?
• Ideas??
Inquiry Lab
• Acids:
• Acids taste sour,
• will change the color of an acid-base indicator,
• and can be strong or weak electrolytes in aqueous solution.
• Bases:
• Bases taste bitter, feel slippery,
• will change the color of an acid-base indicator,
• and can be strong or weak electrolytes in aqueous solution.
The Basics
• Citrus fruits contain citric acid. Tea contains tannic acid.
• Antacids use bases to neutralize excess stomach acid. The base
calcium hydroxide is a component of mortar.
Examples
• 1) Arrhenius Acids and Bases
• 2) Bronsted-Lowry Acids and Bases
• 3) Lewis Acids and Bases
• All three have a different definition for acids and bases,
yet all are VALID.
Types of Acids and Bases
Arrhenius said that acids are hydrogen-containing
compounds that ionize to yield hydrogen ions (H+) in
aqueous solution.
• Hydrochloric Acid
Arrhenius Acids
Monoprotic acids:
Acids that contain one ionizable
hydrogen, such as nitric acid
(HNO3)
Diprotic acids:
Acids that contain two ionizable
hydrogens, such as sulfuric acid
(H2SO4)
Common Acids
Triprotic acids:
Acids that contain three
ionizable hydrogens, such as
phosphoric acid (H3PO4)
• He also said that bases are compounds that ionize to yield
hydroxide ions (OH–) in aqueous solution.
Arrhenius Bases
Common Bases
• The Brønsted-Lowry theory defines:
• Bronsted-Lowry Acid: hydrogen-ion donor
• Bronsted-Lowry Base: hydrogen-ion acceptor
Bronsted-Lowry Acids
Why is ammonia a base and water an acid?
Bronsted-Lowry Acids
• Conjugate acids and bases:
• A conjugate acid is the particle formed when a base gains a
hydrogen ion.
• A conjugate base is the particle that remains when an acid has
donated a hydrogen ion.
Bronsted-Lowry
• A conjugate acid-base pair consists of two substances
related by the loss or gain of a single hydrogen ion.
Bronsted-Lowry
• A substance that can act as both an acid and a base is said
to be amphoteric.
• Water is amphoteric. Sometimes it behaves like a base, and sometimes it
behaves like an acid in terms of Bronsted-Lowry
Bronsted-Lowry
• Lewis acid: accepts a pair of electrons to form a covalent
bond.
• Lewis base: donates a pair of electrons to form a
covalent bond.
Lewis Acids and Bases
WRITE ME DOWN!
Summary
Practice
Practice
• 1) Write chemical equations for:
• The ionization of HNO3 in water
• The reaction of CO3-2 in water
• For each, identify the Bronsted-Lowry acid and base and label the
conjugate acid and base pairs.
• 2) Identify the follow acids as monoprotic, diprotic, or
triprotic. Explain your reasoning.
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H2CO3
H3PO4
HCl
H2SO4
Assignment
• On a piece of paper, summarize your notes by creating a
diagram that organizes all three types of acids. Include:
• Definitions
• Examples of Acids and Bases in Each Type
• Any other pertinent information associated with each type
• Page 625 #45, 46, 48, 49
Assignment