my teacher has set us some science homework which i don't undrestand

What is the chemical change when a candle is lit

When a candle is lit, a chemical change called combustion occurs. During combustion, the heat from the flame causes the wax in the candle to vaporize. The vaporized wax then reacts with the oxygen in the air, producing carbon dioxide gas (CO2) and water vapor (H2O).

To better understand this chemical change, let's break it down step by step:

1. Ignition: When you light a candle, the heat from the flame melts the wax near the wick, which is composed of long-chain hydrocarbons. These hydrocarbons are the fuel for the combustion reaction.

2. Vaporization: As the wax melts, it also starts to evaporate, turning into a gas. The heat from the flame provides the energy necessary for the wax molecules to break free from their solid form and become gaseous.

3. Combustion: Once the wax vapor mixes with oxygen in the air, it undergoes a chemical reaction. The hydrocarbon molecules in the wax combine with oxygen (O2) molecules to produce carbon dioxide (CO2) and water vapor (H2O). This process releases energy in the form of heat and light.

The chemical equation for the combustion of a hydrocarbon in a candle can be represented as follows:

Hydrocarbon (wax) + Oxygen (from air) → Carbon Dioxide + Water Vapor

Please note that the exact composition of the candle wax may vary, as different types of candles use different types of wax. Nonetheless, the overall process of combustion is similar in most cases.

To fully understand the chemical changes occurring during the combustion of a candle, it is helpful to study the concepts of chemical reactions, hydrocarbons, and combustion reactions in more detail. Your teacher may have provided additional resources or textbooks for you to consult. Additionally, online research or asking your teacher for clarification can also be beneficial.