Question

You have a balloon that is filled with 1000 cm3 of air. The balloon is inside your house where the temperature is 20°C. You take the balloon outside where the air temperature is 10°C. Assume the pressure on the air inside the balloon remains constant. Select all of the correct descriptions below for what happens to the air in the balloon.

When the balloon is outside the house, it has a volume less than 1000 cm^3.
When the balloon is outside the house, it has a volume greater than 1000 cm^3.
Heat energy was added to the air in the balloon.
Heat energy was removed from the air in the balloon.
The air in the balloon did work on the atmosphere.
The atmosphere did work on the air in the balloon.

Answer 1

The correct description for what happens when a balloon with 1000 cm3 of air is taken from 20°C indoors to 10°C outside, while maintaining constant pressure, is that the balloon's volume will decrease and heat energy is removed from the air in the balloon. No work is done by or on the gas in the balloon.

Step-by-step explanation:

When the balloon filled with 1000 cm3 of air is taken from a warmer environment (20°C) to a cooler one (10°C), and if we assume the pressure remains constant, according to Charles's Law, the volume of the air in the balloon would decrease. Therefore, the correct description is that when the balloon is outside the house, it has a volume less than 1000 cm3.

The decrease in temperature means that heat energy was removed from the air in the balloon. Since the question implies constant pressure and it does not mention that the balloon is expanding or contracting actively, there is no work being done by or on the gas, so the last two options about the balloon doing work on the atmosphere or vice versa would not apply.

Answer 2

The first option is correct.

Heat energy was removed from the air in the balloon.

The air in the balloon did work on the atmosphere.

Step-by-step explanation:

When the pressure is constant V/T is constant for a gas.

So 1000/ 293 = V / 283 (where the temperature is in degrees K.)

So the volume will decrease from 1000 cm^3.

Also as the temperature outside is colder the air in the balloon lost energy.