Hanging Water

Concept: Pressure. Air Pressure

Materials:

Glass of water

1/2 piece of construction paper

A piece of nylon

2 g of sodium polyacrylate

beaker

Directions:

1. Fill a glass of water up, and hold a piece of construction paper over it tightly.

a. Tip the glass over while still holding the construction paper to it.

b. After a few seconds remove your hand, the paper should stay there for at least thirty seconds.

2. Place a piece of nylon over a glass.

a. Secure the nylon with a rubber band.

b. Fill the glass with water by pouring through the nylon.

c. Tip the glass over, the water does not pour out.

3. Have a glass with the sodium polyacrylate already present. Pour a glass of water into the beaker. Tip the glass upside down to show that nothing is needed to prevent the water from falling out.

Introduction:

How many of you had something to drink in a glass, and your parents told you to be careful not to spill it? How many of you actually have spilled a glass of water before? That happens to a lot of us. Well, boys and girls today, I am going to show you three different ways in which I can put water into a glass, tip the glass over, and the water will not fall out, are you ready?

Explanation:

The first and second parts of the experiment have the same explanation. The air around us is always pushing against something. It pushes in every direction. When the glasses were turned over, the water was pushing on the construction paper and the nylon. However, the air is also pushing up on the paper and nylon. This pressure is greater than the pressure from the weight of water. That is called air pressure and that is what keeps the water in the glass. The glass covered with the nylon has an additional factor of surface tension of the water clogging the holes along with the air pressure to keep the water in the glass.

The third beaker had a substance called sodium polyacrylate. This is the same reaction that was shown earlier called solid water. Osmosis occurred with the powdered sodium polyacrylate in this beaker. Osmosis is the process when water moves through a membrane to an area of higher concentration. Sodium polyacrylate, is a powder that contains a high number of sodium ions. Water is highly attracted to sodium ion, so when the water was poured into the beaker it moved directly into the powder and expanded the polymer to become a solid.

Safety Precautions:

Be careful when handling the sodium polyacrylate.

Handle all glassware with caution. Use a tube or beaker to catch the water in case the demo does not work the first time.

Waste Disposal:

Put sodium polyacrylate in drain and flush with lots of water.

References: Unknown