CHEM: I've never seen Giselle dance like that

What’s combustion?

What’s combustion?

Burning

Oxygen reacts with substances to produce oxides in an exothermic (giving out heat) reaction

Combustion of magnesium

2Mg (s) + O2 (g) → 2 MgO (s)

Intense white flame; white powder produced

Combustion of hydrogen

2H2 (g) + O2 (g) → 2H2O (l)

Water and thermal energy (heat) is produced

Combustion of sulphur

S (s) + O2 (g) → SO2 (g)

Blue flame. Colourless, poisonous gas produced.

What is thermal decomposition?

When a substance breaks down due to the action of heat

Typical thermal decomposition of metals on the lower end of the reactivity series

metal carbonate → metal oxide + carbon dioxide

Thermal decomposition of copper (II) carbonate

CuCO3 (s) → CuO (s)

copper carbonate is green powder

copper (ii) oxide is a black powder