Water compressed? What happens???

Question

Im working on a science fair project. I'm using a syringe and connecting it with another syringe. between the syringes are tubes to connect them. Im putting air and water into it. I'm trying to figure out what is easier to push air or water?? please help me! i need to know what happens to water when u compress it. What happens to its molecules??

Answer 1

Water can be compressed. Anything can be compressed. When you compress something you are pushing the molecules closer together in the phase that they are in.

Water, doesn't like this too much, so it is not as easy to compress as air. The reason it doesn't like it, is that water as a liquid exists in a solution with itself in which all the water atoms are hydrogen bonded with each other at the perfect separation distance.

When you put pressure on the surface of the liquid, you are disrupting this force, in essence, you are fighting the hydrogen bonding. If you push hard enough, you will win, and the molecules will move closer together.

You create a lot of kinetic energy in doing this are can create what is know as a water hammer - here's a reference that discusses the physics of water compression:

http://www.du.edu/~jcalvert/tech/fluids/waterham.htm

Answer 2

You can compress water, or almost any material. However, it requires a great deal of pressure to accomplish a little compression. For that reason, liquids and solids are sometimes referred to as being incompressible. To understand what happens, remember that all matter is composed of a collection of atoms. Even though matter seems to be very solid, in actuality, the atoms are relative far apart, and matter is mostly empty space. However, due to the forces between the molecules, they strongly resist being pressed closer together, but they can be. You probably have experienced compressing something as hard as steel. Have you ever bounced a steel ball bearing off a sidewalk? When you do that, the 'bounce' is due to compressing the steel ball, just a tiny little spot that comes into contact with the sidewalk. It compresses and then springs back, causing the bounce. The water at the bottom of the ocean is compressed by the weight of the water above it all the way to the surface, and is more dense than the water at the surface. A consequence of compressing a fluid is that the viscosity, that is the resistance of the fluid to flow, also increases as the density increases. This is because the atoms are forced closer together, and thus cannot slip by each other as easily as they can when the fluid is at atmospheric pressure.

Answer 3

Water in it's liquid phase is an incompressible fluid. That is, adding pressure to liquid water will not result in a significant reduction in volume.

The air in your experiment is a gas, a compressible fluid. Gases and liquids are both fluids, but liquids are incompressible.

Answer 4

You can't compress water. But water expands. I believe water is harder to push because of pressure, additional its bouyant force.

Answer 5

water doesnt compress