question_answer 1)

  Which of the following statements is correct? (a) The presence of reacting species in a covered beaker is an example of open system. (b) There is an exchange of energy as well as matter between the system and the surroundings in a closed system. (c) The presence of reactants in a closed vessel made up of copper is an example of a closed system. (d) The presence of reactants in a thermos flask or any other closed insulated vessel is an example of a closed system.

Answer:

  (c) If a closed reaction vessel is made of copper, it will work as closed system because in such system heat will be exchanged with the surroundings but no matter will exchange.