Which of the following events is endothermic?

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

Answer: (C)

Verified step by step guidance

1. Understand the definition of endothermic and exothermic processes: Endothermic processes absorb heat from the surroundings, while exothermic processes release heat to the surroundings.
2. Analyze each event in terms of heat flow: For neutralization of hydrochloric acid with sodium hydroxide, this is typically an exothermic reaction because it releases heat.
3. Consider condensation of water vapor: Condensation is the phase change from gas to liquid, which releases heat, so it is exothermic.
4. Examine melting of ice: Melting is the phase change from solid to liquid, which requires absorption of heat, making it an endothermic process.
5. Look at combustion of methane: Combustion reactions release energy in the form of heat and light, so they are exothermic.