Question

Which of the following is an example of an open system?

A. A beaker full of water

B. An air-tight container

C. Vacuum chamber

D. None of the above

Answer 1

Hint:  You can start by briefly defining isolated, open, and closed systems. This will help you choose from the options given to us in the problem, also explain your choice in terms of mass interaction (exchange of mass between thermodynamic systems) and energy interaction (exchange of energy between thermodynamic systems).

Complete answer:

Before attempting the solution, let’s first discuss open systems, closed systems, and isolated systems.

Karl Ludwig von Bertalanffy (an Austrian biologist also known as one of the founders of general systems theory) described two types of systems: open and closed systems.

Only two types of interactions take place in any thermodynamic system: Mass interaction (exchange of mass between thermodynamic systems) and energy interaction (exchange of energy between thermodynamic systems). Let us see different types of systems.

Isolated system – In an isolated system, there is no exchange of mass and heat energy between the surroundings and the isolated system. An example of an isolated system is a perfectly insulated closed air-tight container.

Closed system – In a closed system, the matter inside cannot go outside (and the matter outside cannot come inside) but the energy can exchange between the surrounding and the system through the walls of the closed system. An example of a closed system is a cup of tea with a closed lid on it.

Open system – In an open system the system is open, it means that heat energy and matter can transfer freely between the surrounding and the containers. An example of an open system is a beaker full of water. 

In a beaker full of water the water molecules can escape the beaker and the heat energy from the beaker and the surrounding can exchange with each other.

So, the correct answer is “Option A”.

Note:

Open systems are present all around us from our bodies to the sea and the oceans. We are open systems because matter moves in and out constantly of our body (the air we breathe and exhale, the water we drink and eject from our body) and the energy also transfers from our bodies to the surroundings and vice versa.