The question presents 4 scenarios in which one does not agree with the properties of fluids, so we will look at each option:
"Allowing 5 L of compressed air to expand to a volume of 100 L"
Gaseous mixtures will follow the gas law of PV = nRT. If a 5 L volume of gas were to expand to 100 L, the system would simply decrease significantly in pressure to make up for the increased volume. Therefore, this scenario is allowed.
"Filling a balloon using helium gas from a pressurized tank"
In this scenario the gas is in a container with a very high pressure, and the helium is moving to a balloon which is a container of a much lower pressure. Gas will certainly move from an area of high pressure to an area of low pressure, therefore, this scenario is allowed.
"Compressing 10 L of oxygen gas into a 1 L volume"
Again, following PV = nRT, a 10 L volume of oxygen that is compressed to 1 L will simply result in a system of much higher pressure to make up for the decreased volume, and this scenario is allowed.
"Compressing 2 L of water into a 1 L volume"
While gases can certainly be compressed into smaller volumes or expand into greater volumes, the same is not necessarily true for pure liquids. A 2 L volume of water cannot be compressed to fit into a 1 L container as the pure liquid has a finite volume. Therefore, the correct answer is: Compressing 2 L of water into a 1 L volume
