Chemical reactions and word equations!

Page 1

Key words:

Chemical reaction

Reactant

Product

Formula

Chemical Reactions:

A teacher heats a small piece of sodium. When the sodium catches fire, she places it in a flask of chlorine. The sodium continues to burn. White fumes are produced.

Sodium Reacts vigorously with chlorine

Atoms of sodium and chlorine have joined together to make a new substance, sodium chloride.

There are millions of possible chemical reactions. In all of them, the atoms of the starting materials (or reactants) are rearranged to make new substances (or products). The properties of the products are different from those of the reactants.

Most chemical reactions are irreversible. Once a reaction has happened, it is difficult to get the starting materials back again.

Word equations:

The teacher uses a word equation to summarise the reaction of sodium and chlorine.

sodium + chlorine= Sodium chloride

Word equations show the reactants and products of chemical reactions. But they do not tell us much else. To explain how the atoms are rearranged in a reaction, or to work out the amounts of substances that react together, you need a symbol equation.

New Page