ACIDS & BASES
Neutralization:
ACID + BASE SALT + WATER
pH = Power of Hydrogen (0-14)
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0 - 6.9 = Acidic
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7 = Neutral
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7.1 - 14 = Alkaline
x-axis (Independent)
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An acid is a substance that produces H+ ions in aqueous solution
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Acids contain hydrogen
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Can be neutralized with alkalis
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Acid + water solution will conduct electricity
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Weak acids taste sour
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Acids turn litmus red
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pH below 7
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A soluble base is alkaline
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An insoluble base is a base
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Bases are substances that neutralize acids
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Bases are hydroxides and oxides of metals
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Alkalines release OH- ions in aqueous solution
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An indicator is a dye or mixture of dyes which change color according to its acidity/alkalinity
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Litmus (Red in acid & Blue in base). Available in liquid and paper.
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Universal indicator has a range of colors to tell acidity/alkalinity of solution
Acids
Bases & Alkalines
Indicators
Acid - Sour in taste
Base - Bitter in taste
2 Types of Acids (Depending on Source):
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Organic (naturally weak acids) - E.g. citric acid
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Mineral/Inorganic - E.g. nitric acid
y-axis (Dependent)
In physical change, the chemical composition does not change
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Thermal decomposition - When a compound is heated and thus broken down into two or more simpler substances.
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Reactions that take place inside the body are called biochemical reactions.
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For Conduction of Electricity:
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Solids - Delocalized free moving electrons
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Liquids - Free moving ions
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Acids have H+ ions, so they can conduct electricity in aqueous solution (acid + water)
A stronger acid means it has more H+ ions and will be a better electrical conductor than a weak acid.
Types of Reactions
*Reactive metals below hydrogen in the reactivity series will not give off hydrogen gas when reacting with acids. E.g. copper
Theories
Lewis Theory
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A base is a substance that donates a pair of electrons
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An acid is a substance that accepts a pair of electrons
Arrhenius Theory ​
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Acids release H+ ions in water
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Bases release OH- ions in water
Bronsted Lowey Theory​
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Bases are any substance that will accept a proton
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Acids are any substance that can donate a proton
HCl (g) - Hydrogen chloride (no acidic properties)
HCl (aq) - Hydrochloric acid (acidic properties)
All hydroxides are insoluble except for:
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First group hydroxides
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Ammonium hydroxide
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2nd Group: Calcium, Barium and Strontium hydroxides are partially soluble
Basicity of an acid - Number of replacable H+ ions in one molecule
Deassociation / Ionization
Oxide is a binary compound of oxygen (2 elements only)
