Calcium chloride, CaCl2, is used in “hot packs”. When the solid is mixed with water, the products are favored. Based on this information, which of the following is true for the values of ΔH and ΔS for the dissolving process?

CaCl2 (s) → Ca2+ (aq) + 2 Cl− (aq)

A)ΔH is positive ΔS is equal to zero
B)ΔH is negative TΔS must be positive
C)ΔH is positive ΔS is positive
D)ΔH is positive ΔS is negative
E)ΔH is negative TΔS is small compared with ΔH

2 answers

An exothermic reaction has dH - so it must be B or E
I agree with DrBob222's response it's an exothermic reaction because the temp rises so B or E