alleryStart learning →Which of the following is an example of an **isolated** thermodynamic system?
- Hot tea in an open cup placed on a table
- A reaction mixture in a sealed copper vessel
- Boiling water in a closed glass beaker
- Hot coffee in a thermos flask sealed with its lid
Show answer and solution
Correct answer: D. Hot coffee in a thermos flask sealed with its lid
An isolated system permits neither matter nor energy exchange with the surroundings.
A well-sealed thermos flask is designed precisely for this — vacuum jacket blocks heat transfer, the lid blocks matter exchange.
The open cup is an open system (matter + energy).
The sealed copper vessel is a closed system (no matter exchange, but copper conducts heat).
The closed glass beaker is also closed (glass still conducts heat).