Chapter 11- Acids and Bases

Acids

Acids

Substances that dissociate in water to give H+ ions.

Oxides

Compounds of any other element with oxygen.

Bases

Any metal oxides /hydroxides that react with an acid to produce salt and water only.

soil acidity

To reduce ________, bases like calcium carbonate are spread on the soil.

Uses

fertilizers, cleaning metals, to give a sour taste

Uses

relieving gastric pain, reducing soil acidity, fertilizers

Acidic Oxides

Most oxides of non-metals that have acidic properties.

Basic Oxides

Most oxides of metals that have basic properties.

Amphoteric Oxides

Metallic oxides that react with both acids and bases to form salt and water.

Neutral Oxides

Non-metallic oxides with neither acidic nor basic properties, and are insoluble in water (except water itself).

Burning sulfur to get sulfur dioxide (exothermic)

S + O2 SO2

Catalytic oxidation to get sulfur trioxide (exothermic)

2SO2 + O2 ⇌ 2SO3

Making oleum

H2SO4 + SO2 H2S2O7

Dilution Tower

H2S207 + H20 2H2SO4

Temperature

450⁰C

Pressure

1 to 2 atm

Catalyst

Vanadium pentaoxide/ Vanadium (V) Oxide

Uses of Sulfuric acid

Manufacture of detergents, battery acids and sulfuric acid

Uses of sulfur dioxide

Manufacture of sulfuric acid and wood pulp, used as a bleach and food preservative

Alkali

A base that is soluble in water, and produces hydroxide (OH-) in an aqueous solution.

Litmus

A coloring material that turns red in acid solutions and blue in alkaline solutions.

Concentration

Moles of acid per dm3.

Strong Acids

Any acid that ionises completely in solutions.

Weak Acids

Acids that don't completely dissociate in solutions.