Silver chloride and silver bromide have experimentally determined molar enthalpies of…
CHEMISTRY · Multi-part · AP · Chemistry · Thermodynamics and Electrochemistry · Thermodynamics and Electrochemistry
Problem
Silver chloride and silver bromide have experimentally determined molar enthalpies of solution that are both approximately +56 kJ mol⁻¹, yet AgCl is noticeably more soluble in water at 25 °C than AgBr.
Use molecular-level reasoning to account for this difference.
(a) Describe two distinct molecular processes that contribute to the entropy change when an ionic solid dissolves in liquid water.
(b) Explain why the entropy change accompanying dissolution of AgCl is likely to be more positive than that for AgBr.
(c) Using your explanation from part (b), account for the observed difference in solubility between AgCl and AgBr despite their similar enthalpies of solution.