Which of the following statements best defines a spontaneous process?
It occurs without the need for external intervention under specific conditions.
It occurs instantly without any energy change.
It involves a decrease in disorder within the system.
The correct answer and explanation is:
The correct answer is: It occurs without the need for external intervention under specific conditions.
A spontaneous process is one that occurs naturally without the need for outside energy or intervention. However, it is important to note that the term “spontaneous” does not mean that the process happens immediately or quickly. Instead, it refers to the process occurring naturally when the appropriate conditions are met.
Spontaneous processes are often associated with changes that increase the disorder, or entropy, of a system. For example, when ice melts at room temperature, it is a spontaneous process because it happens naturally without the need for external intervention, as long as the temperature is above the melting point. Similarly, the diffusion of gases in a container is another example of a spontaneous process, driven by the natural tendency for particles to spread out and fill available space.
While a spontaneous process typically leads to an increase in disorder (entropy), there are instances where a decrease in disorder can also occur spontaneously. The key is the balance between the system’s internal energy and entropy. In many cases, processes that lower the system’s energy (such as heat transfer from a hot object to a cold one) also increase the entropy, making the process spontaneous.
It is important to distinguish that spontaneous processes do not necessarily involve instantaneous changes, nor do they imply that no energy changes occur. In fact, spontaneous processes often involve energy changes, such as the release of heat (exothermic reactions) or the absorption of heat (endothermic reactions), depending on the specifics of the process. The key idea is that the process can happen on its own when the right conditions are present.