KIMIA

                                   SYSTEM AND ENVIRONMENT

Basically, the change in enthalpy is due to the energy transfer between the system and the environment. The system is something that has become the focus or center of observation. The environment is an area outside of the system. For example, in the process of ice melting, which is seen as the system is water and ice, while the outside air as the environment. If a reaction takes place in a beaker. Substances that act as the system reacts, beaker as limiting reaction, and everything outside the beaker to act as the environment. Based on the energy transfer between the system and the environment, grouped into thermochemical reaction exothermic reactions and endothermic reactions.

                          OPEN AND CLOSED SYSTEM

There are several types of systems, which is an open system and closed system

** An open system is a system that allows the exchange of matter and energy between the system and environment. Examples of open systems are plants, animals and vegetation usually absorb water and carbon dioxide from the environment (an exchange of material). Plants also need heat emitted by the sun (exchanging energy). You and me as well, including open systems contrast

** Closed system is a system that does not allow the exchange of material between the system with the environment. Said to be isolated if a closed system is not the possibility of energy exchange between systems denganlingkungan. Closed system can be said to be isolated if there is an exchange of energy between the system with an isolated example of a closed system is a thermos of hot water. The inside walls of a thermos of hot water are usually made ​​of an insulating material (in this case, the insulator material that does not conduct heat). Btw, in reality there are many artificial isolated system which is not very ideal. Minimal energy that moves out there, but these are very small