Question

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. of the increase in disorder upon dissolution of this strong electrolyte
B. osmotic properties predict this behavior
C. of the increase in enthalpy upon dissolution of this strong electrolyte
D. the vapor pressure of the water decreases upon addition of the solute
E. of the decrease in enthalpy upon addition of the solute

Answer 1

Answer:

A.

Explanation:

For a process that occurs at constant temperature and pressure, spontaneity can be determined using the change in Gibbs free energy, which is given by:

ΔG = ΔH - TΔS. A process is spontaneous if ΔG≤O.

Even so the enthapy of the dissolution is positive the factor -TΔS will produce a negative ΔG  value. As ΔS is relatived to the disorder of a system, a increase in this value (ΔS ) upon dissolution will made the dissolution process spontaneous.