Calcium Sulfate Is a Desiccant Used for Storage of Samples

Multiple Choice

Calcium sulfate is a desiccant used for storage of samples and equipment in a dry atmosphere because it absorbs water from air. The relevant thermodynamic reaction equation is given below. At what temperature will this reaction reverse to release the water and regenerate the dry desiccant? H   104.9 kJ/mol, S   291.2 J/(mol K)

A) 58C
B) 78C
C) 98C
D) 68C
E) 87C