Glass and clay ceramics

Glass ceramics

Glass is transparent and hard but it is brittle.

Glass shatters when it is hit or dropped
Glass shatters when it is hit or dropped

Most of the glass we use is soda-lime glass. This is made by melting a mixture of sand (silicon oxide), sodium carbonate and limestone, then allowing the molten liquid to cool and solidify.

Borosilicate glass is made by heating sand with boron trioxide. Borosilicate glass has a much higher melting point than soda-lime glass.

Question

State and explain which type of glass would be best to make a boiling tube, for use in a school chemistry laboratory.

Borosilicate glass would be best because it has a higher melting point than soda-lime glass. This means that it will not melt when it is heated using a Bunsen burner.

Clay ceramics

Clay ceramics include brick, china and porcelain. They are made by shaping wet clay and then heating it to a high temperature in a furnace, which causes crystals to form and join together.

Clay ceramics are often coated with a glaze, which hardens on heating to form a hard, smooth, opaque and waterproof layer. This explains why they are often used for dinner plates and bowls.

Brick is strong in compression - it resists being squashed
Brick is strong in compression - it resists being squashed