10.1 g CaO is dropped into a styrofoam coffee cup containing 157 g H2O at 18.0°C. If the following reaction occurs, then what temperature will the water reach, assuming that the cup is a perfect insulator and that the cup absorbs only a negligible amount of heat? (the specific heat of water = 4.18 J/g·°C)
CaO(s) + H2O(l) → Ca(OH)2(s) ΔH°rxn = –64.8 kJ/mol
(A) 18.02°C
(B) 35.8°C
(C) 311°C
(D) 42.2°C
(E) 117°C
