Question

a given container of 5.0 kg of water maintains a constant temperature over 24 hours. if its mass doesnt change, what statements would support identifying it as a closed system. i. only energy was exchanged with its surroundings. ii. its mass was constant because the water lost to evaporation was replaced with an equal volume of water. iii. it didnt exchange matter or energy with its environment. iv. external work was used to maintain its internal energy. a ⅲ b ⅰand ⅲ c ⅱand ⅳ d ⅰand ⅳ

Explanation:

A closed system allows energy exchange with surroundings but no matter exchange.

• Statement I: Closed systems can exchange energy, so this is false.
• Statement II: Mass stays constant in a closed system; evaporation (mass loss) being replaced implies no net mass change, so this is true.
• Statement III: Closed systems exchange energy, so this is false.
• Statement IV: External work (e.g., to maintain temp) involves energy exchange, which closed systems allow, and internal energy is stabilized, so this is true.

Answer:

C. II and IV