Understanding redox reactions with examples

10 Examples of Redox Reactions and How to Balance Them

Example 1: Hydrogen and fluorine combining to form hydrogen fluoride:

$ \text{H}_2 + \text{F}_2 \rightarrow 2\text{HF} $

Example 2: Sodium and chlorine reacting to form sodium chloride:

$ 2\text{Na} + \text{Cl}_2 \rightarrow 2\text{NaCl} $

Example 3: Iron(III) oxide reacting with carbon monoxide to form iron and carbon dioxide:

$ 2\text{Fe}_2\text{O}_3 + 3\text{CO} \rightarrow 4\text{Fe} + 3\text{CO}_2 $

Example 4: Hydrogen peroxide decomposing into water and oxygen:

$ 2\text{H}_2\text{O}_2 \rightarrow 2\text{H}_2\text{O} + \text{O}_2 $

Example 5: The reaction between zinc and hydrochloric acid to form zinc chloride and hydrogen gas:

$ \text{Zn} + 2\text{HCl} \rightarrow \text{ZnCl}_2 + \text{H}_2 $

Example 6: The reaction between potassium permanganate, sodium sulfite, and water to form manganese dioxide, potassium sulfate, and sodium sulfate:

$ 2\text{KMnO}_4 + 5\text{Na}_2\text{SO}_3 + 3\text{H}_2\text{O} \rightarrow 2\text{MnO}_2 + 5\text{Na}_2\text{SO}_4 + 2\text{KOH} $

Example 7: The reaction between sodium and water to form sodium hydroxide and hydrogen:

$ 2\text{Na} + 2\text{H}_2\text{O} \rightarrow 2\text{NaOH} + \text{H}_2 $

Example 8: The reaction between copper(II) sulfate and zinc to form zinc sulfate and copper:

$ \text{CuSO}_4 + \text{Zn} \rightarrow \text{ZnSO}_4 + \text{Cu} $

Example 9: The reaction between hydrogen and nitrogen to form ammonia:

$ 3\text{H}_2 + \text{N}_2 \rightarrow 2\text{NH}_3 $

Example 10: The reaction between magnesium and oxygen to form magnesium oxide:

$ 2\text{Mg} + \text{O}_2 \rightarrow 2\text{MgO} $

To balance these reactions, you ensure that the number of atoms of each element is the same on both sides of the equation. This often involves adding coefficients (the numbers in front of the chemical formulas).