Question 17

NH4NO3 + H2O + energy → NH₄OH + HNO₃

This equation accurately represents the endothermic reaction that occurs when solid ammonium nitrate dissolves in water, producing ammonium hydroxide and nitric acid while absorbing energy.

A) NH₄OH + HNO₃ → NH₄NO₃

This option incorrectly depicts the reaction as a product formation. It suggests that ammonium hydroxide and nitric acid combine to form ammonium nitrate, which does not reflect the dissolution and dissociation process occurring with ammonium nitrate in water.

B) NH4NO3 + H2O + energy → NH₄OH + HNO₃

This option correctly illustrates the endothermic process where solid ammonium nitrate absorbs energy upon dissolving in water, resulting in the formation of ammonium hydroxide and nitric acid, aligning with the description of the chemical reaction provided.

C) NH₄NO₃ + H₂O → NH4OH + HNO3 + energy

This option is incorrect as it suggests that energy is released during the reaction. Since the reaction is endothermic, it should indicate energy absorption, not release, making this representation inaccurate.

D) NH4OH + HNO3 + energy → NH₄NO₃ + H₂O

This choice also misrepresents the reaction by indicating that ammonium hydroxide and nitric acid combine to form ammonium nitrate and water while releasing energy, which contradicts the endothermic nature of the actual reaction.

Conclusion

The correct answer, B, accurately describes the endothermic process of ammonium nitrate dissolving in water to form ammonium hydroxide and nitric acid while absorbing energy. All other options either misrepresent the direction of the reaction, the energy flow, or the products formed, thus failing to depict the chemical process correctly.