How are equations used to represent chemical reactions?Using state symbols in chemical equations
All substances are described by their formulae, which are used to write balanced chemical equations. Writing the formula for an ionic compound requires knowledge of the charges on its ions.
State symbols give more information about the reactantA substance that reacts together with another substance to form products during a chemical reaction. and productA substance formed in a chemical reaction..
State symbol
Meaning
(s)
solid
(l)
liquid
(g)
gas
(aq)
aqueous (dissolved in water)
State symbol
(s)
Meaning
solid
State symbol
(l)
Meaning
liquid
State symbol
(g)
Meaning
gas
State symbol
(aq)
Meaning
aqueous (dissolved in water)
Question
An iron nail is placed in a solution of blue copper(II) sulfate. Over time, a brown solid appears and the solution becomes colourless. This is because copper and a solution of iron(II) sulfate forms.
Add state symbols to the balanced chemical equationA chemical equation written using the symbols and formulae of the reactants and products, so that the number of units of each element present is the same on both sides of the arrow. for the reaction of iron with copper(II) sulfate.