Properties of Water Labs
1. Evaporative Cooling. Water and Alcohol
In this lab we placed a drop of water and a drop of alcohol on the back of our hands and feel which one was cooler.
In the end the water felt a little bit more cooler than the alcohol. Water can absorb much more heat than alcohol,so when it evaporates it evaporates all the heat with it. So that's the reason why the water felt cooler.
In the end the water felt a little bit more cooler than the alcohol. Water can absorb much more heat than alcohol,so when it evaporates it evaporates all the heat with it. So that's the reason why the water felt cooler.
2. Water tension and Cohesion. Water on a penny
This lab we had to count the number of drops a penny can hold before the water spilled. First though we had to guess and my guess was 24 drops. The actual answer is 29. I think the reason it can hold that many drops was because of cohesion. Cohesion allows water molecules to be attracted to each other. So it allowed a little more water to be on the penny.
3. Surface Tension. Water on wax paper
We had to add drops of water on to wax paper and see what happens. What we saw was that the water didn't imediately go through the wax paper. It stayed on top of the wax paper for a while then it slowly went through the wax paper.
4. Surface Tension. Paper Clips on the Surface of a Cup of Water
We had to try and place paperclips on top of the surface of the water. I was using tweezers so it was pretty hard for me to place them on top. In fact I actually couldn't do it. However other people somehow did it. It was because of the water's surface tension. Cohesion allows the surface of the water to have better tension, allowing some things to stay on the water's surface.
5. Adhesion. Graduated Cylinder
We put water in a graduated cylinder and observed the "meniscus." The reason why it's there is because of adhesion. Adhesion is when water sticks to other materials. In this the water is sticking to the surface of the cylinder. Adhesion is also important for living things like plants because then the water can stick to the leaves and roots of it and then capillary action happens and the water goes up the roots for the plant.
6. Capillary Action. Rolled up Paper Towel
In this what we did was put water in one cup, then roll up a paper towel placing one end on the cup with water and the other on the one without water. Then we saw the water go through the towel. Over the next few days the water got transfered from the first cup to the other cup through the towel. This was because of capillary action. It's the combination of both cohesion and adhesion. It allows water to go through certain things, like the paper towel.