Paul J. answered • 05/20/21
Bachelor's of Science in Forensic Chemistry
Choice D is false. An exothermic process is a process in which heat is released to the system's surroundings. Choice D is describing an endothermic process because an endothermic process requires an input of energy in order to initiate a reaction. An endothermic process would absorb thermal energy which would decrease the overall temperature of the reaction's surroundings.
Choice C is also false. Temperature is actually a measurement of the average kinetic energy of a molecule. As temperature increases, molecules will have a higher kinetic energy and therefore move faster. Since an exothermic process releases heat to the surroundings, molecules in the surroundings will begin to move faster because they will absorb more energy, which increases their kinetic energy. Since an endothermic process will remove energy from a system, it will reduce the kinetic energy of molecules within the system, which slows them down. Choice C is also describing an endothermic process.
Choice B does describe an exothermic reaction because exothermic processes transfer energy to the surroundings. Although both endothermic and exothermic processes involve energy transfers, an endothermic process will remove energy from the environment.
A is false because a chemical reaction does not always occur with an exothermic process. A chemical reaction occurs when bonds are broken and formed between atoms, and the identity of a substance is changed once the reaction completes. For example, when water condenses (converts from a gas to a liquid), water molecules must release thermal energy in order to undergo the phase change from gas to liquid. This is an example of an exothermic physical reaction because the chemical identity of the water is not changing, the only thing that changes is the state of matter. Hence, not all exothermic processes are chemical reactions, some of them are physical reactions.
Answer: Choice B
