In which type of reaction does heat flow into the system from the surroundings?

• A. Combustion reaction
• B. Neutralization reaction
• C. Exothermic reaction
• D. Endothermic reaction

Answer: (D)

Verified step by step guidance

1. Understand the concept of heat flow in chemical reactions: heat can either flow into the system (absorbed) or flow out of the system (released).
2. Recall that an exothermic reaction releases heat to the surroundings, so heat flows out of the system.
3. Recognize that an endothermic reaction absorbs heat from the surroundings, meaning heat flows into the system.
4. Identify that combustion and neutralization reactions are typically exothermic, releasing heat rather than absorbing it.
5. Conclude that the type of reaction where heat flows into the system from the surroundings is an endothermic reaction.