• How to Write Chemical Equations Chemical equations can be written in the form of words or using chemical formulae.
• The starting substances or reactants are written on the left-hand side of the equation while the new substances formed or products are written on the right-hand side of the equation.
• The arrow '→’ means ‘produces’.
• The physical state of each substance, whether solid(s), liquid(l), gas(g) or aqueous solution(aq) is usually indicated in a chemical equation.

• The following diagram is the steps in determining the chemical equation:

•  Below shows an example of a chemical equation:
  • \(Mg(s) + 2HCl(aq) \rightarrow MgCl_2(aq) + H_2(g)\)

                 * Note: (s) solid state, (aq) aqueous state and (g) gas state.

• From the chemical equation above, we know, solid magnesium and HCl are the reactants.
• These two reactants react and become magnesium chloride.
• For better understanding, pay attention to the coefficient for each reactant and product in the chemical equation.
  • One mole of magnesium reacts with 2 moles of hydrochloric acid to produce 1 mole of magnesium chloride and 1 mole of hydrogen gas. 

• How to Write Chemical Equations Chemical equations can be written in the form of words or using chemical formulae.
• The starting substances or reactants are written on the left-hand side of the equation while the new substances formed or products are written on the right-hand side of the equation.
• The arrow '→’ means ‘produces’.
• The physical state of each substance, whether solid(s), liquid(l), gas(g) or aqueous solution(aq) is usually indicated in a chemical equation.

• The following diagram is the steps in determining the chemical equation:

•  Below shows an example of a chemical equation:
  • \(Mg(s) + 2HCl(aq) \rightarrow MgCl_2(aq) + H_2(g)\)

                 * Note: (s) solid state, (aq) aqueous state and (g) gas state.

• From the chemical equation above, we know, solid magnesium and HCl are the reactants.
• These two reactants react and become magnesium chloride.
• For better understanding, pay attention to the coefficient for each reactant and product in the chemical equation.
  • One mole of magnesium reacts with 2 moles of hydrochloric acid to produce 1 mole of magnesium chloride and 1 mole of hydrogen gas.