When 10.1 g CaO is dropped into a styrofoam coffee cup containing 157 g H2O at 18.0°C, the temperature rises to 35.8°C. Calculate the enthalpy change of the following reaction in kJ/mol CaO. Assume 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)

15. which of the following is not human-caused groundwater pollution? a. water in an aquifer dissolves elements such as arsenic and mercury from surrounding rock. b. water in an aquifer is contaminated by leachate that seeps into the ground from a landfill. c. water in an aquifer becomes polluted with chemicals used in hydraulic fracturing, or fracking. d. water in an aquifer absorbs harmful bacteria from the drainage field of a septic tank.