Ammonium nitrate is dissolved in water and the temperature of the solution falls. What does this show?
Answer and explanation
Correct answer: B. The process is endothermic
- Step 1: The solution gets colder, so energy transfers from the solution to the dissolving solid.
- Step 2: Absorbing heat from the surroundings is endothermic.
Answer
The process is endothermic.
Why not the others: The process is exothermic: a falling temperature means heat is absorbed. The process has an enthalpy change of zero: a temperature change shows the enthalpy change is not zero. The process is a combustion reaction: dissolving is not a combustion.
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