Two balloons are at the same temperature and pressure, and contain equal volumes of gas, but one is floating, and the other is not. The reason for this behavior is that:
A)the balloon that is not floating has the molecules more closely spaced than the other.
B)the balloon that is not floating has a gas with a higher molar mass than that of air.
C)the balloon that is floating has molecules with more kinetic energy.
D)the balloon that is not floating has molecules that have slowed down, since it was filled before the floating balloon.
E)the balloon that is floating has a more dense gas than the one that is not floating, so it holds up the balloon better.

Question

Quizplus · Accepted Answer

The balloon that is not floating has a gas with a higher molar mass than that of air. This means that the gas inside the balloon is denser than air and therefore, the weight of the gas is greater than the weight of the displaced air. The balloon is heavier than the air around it, causing it to sink. The floating balloon has a gas with a lower molar mass than that of air and therefore is less dense than air, causing it to rise.

Two Balloons Are at the Same Temperature and Pressure, and Contain