Final answer:
The system is the specific part of the universe under study while the surroundings are everything else. Energy flows between the system and surroundings in accordance with the law of conservation of energy, and processes can be exothermic or endothermic. Entropy, a measure of disorder, increases according to the second law of thermodynamics.
Step-by-step explanation:
The difference between a system and the surroundings is fundamental to understanding thermodynamics and the flow of energy in chemical reactions. A system refers to a specific part of the universe that is under study, such as the chemicals involved in a reaction within a flask. The surroundings comprise the rest of the universe, including the container in which the reaction is taking place and everything beyond. Energy exchange during a reaction can occur either from the system to the surroundings or from the surroundings to the system, adhering to the law of conservation of energy. This law states that energy can neither be created nor destroyed, only transformed and transferred.
For example, when a chemical reaction occurs, it can either release energy into the surroundings, known as an exothermic process, or absorb energy from the surroundings, known as an endothermic process. Therefore, when discussing the flow of energy, it's important to specify whether it's entering or leaving the system. Additionally, the concept of entropy, which is a measure of disorder, is crucial. The second law of thermodynamics states that entropy in an isolated system always increases over time, signifying that energy transformations are never completely efficient with some energy always being lost to the surroundings as heat.