Answer
a. Endothermic
b. Exothermic
c. Exothermic
d. Endothermic
Work Step by Step
a. Because the solution feels colder, the solution is absorbing energy and therefore is an endothermic process.
b. When natural gas is burned in a furnace, energy and heat is released, an exothermic process.
c. Because the solution gets hot and therefore releases heat energy, the solution is undergoing an exothermic process.
d. Because water boiling requires the input of heat and absorption of energy, water boiling is an endothermic process.
