Ammonium nitrate (NH₄NO₃)dissolves readily in water even though the dissolution is endothermic by 26.4 kJ/mol. The solution process is spontaneous because __________. A)the vapor pressure of the water decreases upon addition of the solute B)osmotic properties predict this behavior C)of the decrease in enthalpy upon addition of the solute D)of the increase in enthalpy upon dissolution of this strong electrolyte E)of the increase in disorder upon dissolution of this strong electrolyte

Question

Quizplus · Accepted Answer

The increase in disorder upon dissolution of a substance is quantified by its entropy change (∆S), which is expected to be positive for spontaneous dissolution. In this case, ammonium nitrate is a strong electrolyte that dissociates into ions when dissolved in water, leading to a significant increase in the number of particles in the solution and hence an increase in entropy. The endothermic nature of the dissolution (positive ∆H) is offset by the positive ∆S, resulting in a negative Gibbs free energy (∆G) and a spontaneous process. Choices A, B, C, and D do not provide a valid explanation for the spontaneous dissolution of ammonium nitrate.

Ammonium Nitrate (NH4NO3)dissolves Readily in Water Even Though the Dissolution

Ammonium Nitrate (NH₄NO₃)dissolves Readily in Water Even Though the Dissolution