Investigating Water Lab By: Dana Botavon and Neida Osuna

Evaporative Cooling: #1 Water and Alcohol Place a drop of water and a drop of alcohol next to each other on the back of your hand. Which feels cooler? The alcohol feels much cooler than the drop of water. Why is it beneficial that your sweat is water and not alcohol based? Our sweat is water and not alcohol based because our bodies are filled with H20 from what we hydrate into our bodies. So when we sweat, the liquid that is hydrated into our bodies burn out or in other words, sweat.

Water Tension/Cohesion: #2 Water on a Penny Predict how many drops of water you think will fit on a penny: 15 How many drops fit on the penny? How was your penny able to hold that many drops? 32 drops of water fits onto the penny, it was able to hold that much drops because of the penny’s surface, it is round and the cohesion of the water where it was able to stick together as the same particle. Draw a side view of the penny with water on it just before it overflowed. Explain. There are 32 drops of water on the penny, just before it overflows and it held on that much when the water was being dropped onto the penny.

Surface Tension: #3 Water on Parafilm Paper Observations: The water was flowing on the parafilm paper, so did the alcohol too. The water stick together as one substance, in one spot, but the alcohol did not have cohesion, therefor it did not stick together and it was flowing everywhere.

Surface Tension: #3a Paper Clips on the Surface of a Cup of Water How many paperclips floated on the water before it sunk? There was 11 paperclips on the surface of the water before it began to sink. Carefully add one drop of dish soap to the water- what happens now? The paper clips sink to the bottom more quickly and the soap sinks to the bottom or some remains at the surface of the water.

Adhesion: #4 Graduated Cylinder Explain why the water line is not a straight line across in a glass container. The water line is not a straight line across in a glass container because the flow of the water does not stay straight, since its floating inside of the glass container. Why would the water property of adhesion be important in living systems? The water property of adhesion is important in living systems because their cells contain water molecules in them, that is needed for them to live.

Water as a Solvent: #5 Dissolving Do they dissolve? Salt (ionic) - Yes Sugar (polar) - No Oil (nonpolar) - No What characteristic of water allows it to be such a powerful solvent? Name 2 other things that you think would dissolve in water. Why? Food coloring and ice because Name 2 other things that would not dissolve in water. Why? Dish soap and

Capillary Action: #6 Rolled up Paper Towel Watch the transfer from one cup to the other. Why would capillary action be important to plants and trees? Explain. Capillary action is important to plants and trees because they need the water to transfer from the soil, so that they are able to get the water that is needed for their living.

Definitions and Examples Adhesion Define: tendency to stick to other substances Explain how you saw this in today’s lab: We saw this in today’s lab by looking at the dissolving of oil, salt, and sugar. Cohesion Define: tendency to stick to other water substances Explain how you saw this in today’s lab: We saw this in today’s lab by comparing the drop of water and drop of alcohol on a piece of parafilm paper. High Specific Heat Define: Specific heat is the measurement of how much energy it takes to change the temperature of a substance. Water’s specific heat is high so it must absorb a lot of heat to raise its temperature and eventually evaporate. This also means water has to lose more energy for its temperature to drop than most materials. Explain how you saw this in today’s lab: I saw this in today’s lab by looking at the temperature of the water and it was at room temperature, so the water did not heat up or change at all, since it was in the classroom. “The greatest solvent on Earth” Define (or explain this phrase): The greatest solvent on Earth is water. Explain how you saw this in today’s lab: We saw this in today’s lab by going through each step in the water lab and water was the main substance that was used for our little experiments and we were analyzing each one of them, during the whole process.