metal oxides and metal hydroxides

amphoteric

a substance that can act as both an acid and a base, the most common example being aluminium oxide.

acid

compound containing hydrogen that dissociates in water to form a hydrogen ion.

base

a compound that reacts with an acid to form a salt and water (OH- hydroxide ion)

alkaline

is a base that dissolves in water to form hydroxide ions ( alkaline substances provide OH- ions

salt

a compound formed by an acid-based reaction where the hydrogen in the acid has been replaced by a metal or another positive ion.

explain the formation and uses of calcium oxide.

The O2- ion has a small charge, making it a basic ion. This reacts with water to form calcium hydroxide.

CaO + H2O - Ca(OH)2

Calcium oxide and calcium hydroxide are used by farmers to neutralise acidic soil by raising the PH value.

Calcium carbonate used to be heated to form calcium oxide. The then-hot calcium oxide would glow. They would use this light in the theatre.

explain the formation and uses of magnesium oxide.

Magnesium oxide can be a desiccant when preserving books in the library. A desiccant, in connection with books, is a substance used to keep the books dry. However, some papers produce acidic sulphur oxides in presence of oxygen

Sulphur trioxide dissolves in water to produce an acid, sulphuric acid

SO3 + H2O - H2SO4

Sulfuric acid then reacts with magnesium oxide and is neutralised.

magnesium oxide + sulfuric acid + magnesium sulphate + water

MgO + H2SO4 - MgSO4

MGO is used in furnaces in the form of bricks to reflect the heat within the furnace. keeping it hot inside and cool outside.

explain the formation and use of sodium hydroxide

one way to create sodium hydroxide is the reaction of sodium and water

sodium oxide + water = sodium hydroxide

NaO + H2O - Na(OH)

sodium hydroxide can be used to make plastics and soaps

to manufacture food and is found in drain and oven cleaners

explain the formation and uses of magnesium hydroxide

Magnesium hydroxide is known as the milk of magnesia. used to treat acid indigestion and is able to neutralise stomach acid because it is basic in nature.

magnesium hydroxide + hydrochloric acid - magnesium chloride + water

Mg(OH)2 + 2HCL + 2H2O + MgCL2

explain the formation and uses of calcium hydroxide

Calcium hydroxide is used to treat acidic waste; factories that use sulfuric acid use CaOH to reduce the acidity of the waste products.

calcium hydroxide + sulfuric acid + calcium sulphate + water

Ca(OH)2 + H2SO4 - CaSO4 + H2O

Calcium hydroxide is a popular base as it is cheap and simple to use.