What are examples of everyday redox reactions?

Examples of everyday redox reactions include rusting of iron, respiration in humans, and the burning of fuels.

Rusting of iron is a common redox reaction that we observe in our daily life. When iron is exposed to moist air, it reacts with oxygen to form iron(III) oxide, commonly known as rust. This is an oxidation reaction as iron loses electrons to form iron(III) ions. At the same time, oxygen is reduced as it gains electrons to form oxide ions. The overall reaction can be represented as: 4Fe(s) + 3O2(g) → 2Fe2O3(s). This reaction is slow and can take a long time, which is why we see rust forming over time on iron objects left exposed to the air.

Respiration in humans is another example of a redox reaction. It is the process by which our bodies convert glucose into energy. During respiration, glucose is oxidised to carbon dioxide and water, releasing energy. The overall reaction can be represented as: C6H12O6(aq) + 6O2(g) → 6CO2(g) + 6H2O(l). Oxygen acts as the oxidising agent, accepting electrons from glucose. This is a continuous process that occurs in all living cells to provide the energy needed for various bodily functions.

The burning of fuels is a redox reaction that we often see in our daily life. When a fuel, such as wood or petrol, is burnt, it reacts with oxygen in the air to produce heat, light, carbon dioxide, and water. This is an oxidation reaction as the fuel loses electrons. Oxygen is reduced as it gains electrons. The exact reaction depends on the type of fuel, but a general representation is: Fuel + O2(g) → CO2(g) + H2O(g). This reaction is exothermic, meaning it releases energy, which is why we use fuels for heating, cooking, and powering vehicles.

IGCSE Chemistry Tutor Summary: Everyday redox reactions include rusting of iron, human respiration, and burning fuels. In rusting, iron loses electrons to oxygen, forming rust. Respiration converts glucose to energy, with glucose losing electrons to oxygen. Burning fuels releases energy by fuel losing electrons to oxygen, producing carbon dioxide and water. These processes show the transfer of electrons, crucial in redox reactions.