Which of the following processes is endothermic?

• A. Melting of ice
• B. Neutralization of hydrochloric acid with sodium hydroxide
• C. Combustion of methane
• D. Condensation of water vapor

Answer: (A)

Verified step by step guidance

1. Understand the definition of an endothermic process: it is a process that absorbs heat from the surroundings, meaning heat energy is taken in during the change.
2. Analyze each given process in terms of heat flow: - Melting of ice involves changing solid water to liquid water, which requires energy input to break the hydrogen bonds, so it absorbs heat. - Neutralization of hydrochloric acid with sodium hydroxide is a chemical reaction that typically releases heat, making it exothermic. - Combustion of methane is a chemical reaction that releases a large amount of heat, so it is exothermic. - Condensation of water vapor involves gas turning into liquid, releasing heat to the surroundings, so it is exothermic.
3. Identify the process that requires heat absorption (endothermic): melting of ice requires energy input to overcome intermolecular forces and change phase from solid to liquid.
4. Confirm that the other processes release heat (exothermic) and therefore are not endothermic.
5. Conclude that among the options, the melting of ice is the endothermic process.