Question

1. the image shows two setups where a flask containing liquid is being heated. in the first setup (x), the flask is open, and in the second setup (y), the flask is sealed. the student measures the total energy in each system after heating.

image of two flasks, x (open) and y (sealed), with liquid and being heated by burners

which setup demonstrates the conservation of energy in a closed system?

options:

• setup x, because the energy escapes as the liquid evaporates.
• setup y, because the energy is contained within the sealed flask, showing no loss of energy outside the system.
• both setups demonstrate energy conservation because they both involve heating the liquid
• neither setup demonstrates energy conservation because the liquid changes form in each setup.

Explanation:

To determine which setup demonstrates energy conservation in a closed system, we analyze each option:

• For the first option: Setup X is open, so when the liquid evaporates, energy (in the form of the evaporated liquid's energy) escapes to the surroundings. Thus, it does not demonstrate energy conservation in a closed system.
• For the second option: Setup Y is a sealed flask, meaning it is a closed system. In a closed system, energy is contained within the system and is conserved (no energy is lost outside the system). So this setup aligns with the concept of energy conservation in a closed system.
• For the third option: Just because both setups involve heating the liquid does not mean they both demonstrate energy conservation in a closed system. Setup X is open and loses energy, so this is incorrect.
• For the fourth option: The change of the liquid's form (like evaporation) does not mean energy conservation is not demonstrated. In a closed system (Setup Y), even with a phase change, energy is conserved. So this is incorrect.

Answer:

B. Setup Y, because the energy is contained within the sealed flask, showing no loss of energy outside the system.