Chemical Changes in Burning Candle: When you light the candle, the wax present near the wick will melt. Wick absorbs the liquid wax. The liquid wax vaporizes due the heat produced by the flame. This wax vapor near to flame burns and gives new substances like Carbon Dioxide, Carbon soot, water vapours, heat and light.

Burning of wax is a chemical change or irreversible change as it produces water vapour, carbon dioxide and soot and we can not combine them to form the same candle.

Introduction:

The burning of a candle is a chemical change. It involves the process of combustion, which is a type of chemical reaction. When a candle burns, it undergoes various transformations, both physical and chemical, resulting in the release of light and heat.

Physical Changes:

1. Melting of Wax: As the flame of the candle reaches the wax, it melts and forms a pool of liquid wax around the wick. This is a physical change as the state of matter changes from solid to liquid without any alteration in the chemical composition of the wax.

2. Evaporation of Wax: As the candle burns, the heat generated by the flame causes the liquid wax to evaporate. This evaporation is also a physical change, where the liquid wax transforms into a gaseous state.

3. Formation of Soot: When the candle burns, it produces black carbon particles known as soot. These soot particles are formed due to incomplete combustion and are a physical change as the chemical composition of the wax remains the same.

Chemical Changes:

1. Combustion: The primary chemical change that occurs during the burning of a candle is combustion. Combustion is an exothermic chemical reaction between the wax vapor and oxygen in the air. This reaction releases energy in the form of heat and light. The wax molecules break down into carbon dioxide and water vapor, along with the release of energy.

2. Chemical Reactions: During combustion, the hydrocarbon molecules present in the wax react with oxygen to produce carbon dioxide and water vapor. This reaction involves breaking and forming chemical bonds, resulting in the transformation of the wax into new chemical substances.

Conclusion:

The burning of a candle involves both physical and chemical changes. The physical changes include the melting of wax, evaporation of wax, and the formation of soot. On the other hand, the chemical change that takes place is combustion, where the wax molecules react with oxygen to produce carbon dioxide and water vapor. The release of energy in the form of heat and light is a result of these chemical reactions. Overall, the burning of a candle is a fascinating process that showcases the complex interactions between different elements and compounds.