Page 13 - Curriculum Visions Dynamic Book

combustion: the special case of oxidisation of a substance where a considerable amount of heat and usually light are given out. Combustion is often referred to as “burning”.
exothermic reaction: a reaction that gives heat to the surroundings. Many oxidation reactions, for example, give out heat.
oxidation: a reaction in which the oxidising agent removes electrons. (Note that oxidising agents do not have to contain oxygen.)
smoke: a mixture of both small solids and gases.
 In the picture on the left a wax taper is being held in the air above a gas jar of chlorine. The taper burns in the oxygen in the air with a yellow flame, releasing carbon (soot) particles and forming carbon dioxide gas.
However, when the wax taper is introduced to a gas jar of chlorine as shown in the picture on the right, the taper burns with a
red flame. It also liberates carbon particles (soot) and produces a steamy gas – highly poisonous hydrogen chloride – that attracts water vapour in the air
to form tiny droplets of hydrochloric acid. This is not a nice gas to be near!
 Chlorine, containing copper chloride smoke, is denser than air and can therefore be poured from a gas jar.
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