9.2 Glass and Ceramics

9.2 Glass and Ceramics

Silica

the material that contains silicon dioxide that exists naturally in sand

Glass - a hard and transparent material

• Most glass is produced from molten silica.

• Pure silica is melted at around 1500^oC until all becomes liquid and moulded to form glass.

• Glass can be recycled

• Simplest form of glass is fused silica glass

Types of glass: (Refer pg 189)

• fused silica glass

• soda-lime glass

• borosilicate glass

• lead crystal glass

Fused silica glass

- Silica

- Transparent, inert to chemicals, high melting point

Soda-lime glass

- Silica, sodium carbonate, calcium carbonate

-transparent, inert to chemicals, low melting point, easy to mould

Borosilicate glass

- Silica, boron oxide, sodium oxide, aluminium oxide

- transparent, inert to chemicals, high melting point, can withstand wide range of temperature changes

Lead crystal glass

- silica, sodium oxide, lead(II) oxide

- very transparent, shiny, high reflective index, high density

Multiple Select

Tick the correct composition for fused silica glass.

• Silica

• boron oxide

• sodium carbonate

• aluminium oxide

Multiple Select

Tick the correct composition for soda lime glass.

• Silica

• calcium carbonate

• sodium carbonate

• aluminium oxide

Multiple Select

Tick the correct composition for borosilicate glass.

• Silica

• boron oxide

• sodium oxide

• aluminium oxide

Multiple Select

Tick the correct composition for lead crystal glass.

• Silica

• boron oxide

• sodium oxide

• lead(II) oxide

Multiple Choice

Which of the following is made of borosilicate glass?

• Lenses

• Prism

• Laboratory apparatus

• Mirrors

Multiple Choice

Which of the following is made of soda-lime glass?

• Lenses

• Prism

• Laboratory apparatus

• Mirrors

Ceramic -made from clay and composed of aluminium silicate and sand

• White clay - kaolin

• Red clay - consists of iron(III) oxide

• During the making of ceramic, the shaped objects are heated to a very high temperature, undergo a series of chemical reactions and are hardened to form ceramic

• Properties: very hard and strong, brittle, chemically inert and does not corrode, good insulator of electricity and heat, high melting point and can withstand heat

Building materials

Hard and strong

Decorative items

attractive and easy to mould

Kitchenware

Chemically inert and resistant to corrosion

Insulating parts in electrical appliances

electrical insulators

Layer of heat insulator

heat insulator - furnace lining

Medical apparatus

Inert and hard

Glass can be recycled but ceramics cannot.

Explain the above statement.