Sure! Let's classify each chemical or physical change as either an endothermic or exothermic process based on the definition that exothermic processes release heat and endothermic processes absorb heat.
1. Burning a candle: When a candle burns, it releases heat and light energy. This is a classic example of an exothermic process.
- Answer: Exothermic
2. Cooking an egg: Cooking an egg involves absorbing heat from the surroundings (e.g., from the stove or boiling water), causing the egg to transform from a liquid to a solid state. This process requires energy input, thus it is endothermic.
- Answer: Endothermic
3. Rain changing to snow: When rainwater changes state from liquid to solid (snow), it releases latent heat to the surroundings. This release of heat is characteristic of an exothermic process.
- Answer: Exothermic
4. Boiling water: Boiling water involves heating it to the point where it changes from liquid to gas, which requires absorbing heat. Therefore, boiling water is an endothermic process.
- Answer: Endothermic
5. Combustion reaction: The reaction given:
[tex]\[
CH_4 + 2 O_2 \rightarrow CO_2 + 2 H_2O + \text{heat}
\][/tex]
Involves the combustion of methane ([tex]\(CH_4\)[/tex]), which releases heat as a product, indicating it is an exothermic reaction.
- Answer: Exothermic
Therefore, the classifications are as follows:
- Burning a candle: Exothermic
- Cooking an egg: Endothermic
- Rain changing to snow: Exothermic
- Boiling water: Endothermic
- Combustion reaction: Exothermic
Result:
[tex]\[
\text{('Exothermic', 'Endothermic', 'Exothermic', 'Endothermic', 'Exothermic')}
\][/tex]
