Properties of Water Station Lab



Name _________________________________________Block ________Properties of Water Station LabIntroductionWater is everywhere in your world. It makes up about 3/4ths of the surface of the earth. It makes up 50-95% of the weight of living organisms. It is in the air we breathe, the sinks we use and in every cell of the body of every living organism. Water has special properties that make it unusual and complex:Water has the ability to be a liquid, solid or gas depending on the temperature at which it is found.Each molecule of water is made up of 2 hydrogen molecules and 1 oxygen molecule bonded together. Water is a polar molecule because the oxygen molecule has a slightly negative charge and the hydrogen molecules have a slightly negative charge. This polarity results in hydrogen bonds forming between water molecules. Pre-Lab Questions: Answer the following questions using any background knowledge you have concerning water. Your answers DO NOT need to be correct, you are writing your best answer with the current knowledge you have. By the end of the lab, you will answer the questions again using your increased knowledge!How does water rise from the roots of a tree to the very top?How do insects walk on the water?Why does ice float rather than sink?Why do people become seriously ill, or die, if they go without liquid for a week or so?How would life in a lake be affected if ice sank and lakes froze from the bottom up?If ? of our planet are covered in water why should we be worried about conserving water? Station #1: Cohesion1. What is cohesion? 2. Predict how many drops you will be able to put on the penny before it overflows by having each person at your table guess and write the guesses below:Group Member #1: _______Group Member #2: _______Group Member #3: _______3. Draw a diagram showing the shape of the water on the penny after one drop, when the penny is half full and just before it looks like it is going to overflow: After 1 drop: When penny is half full: Just before overflowing:2060575200025411099020129502051054. How many total drops did you get on the penny? __________________5. If the number of drops is different from your prediction, explain your results in terms of cohesion.Station #2 – Surface Tension1. What is surface tension? With your finger, spread one drop of detergent on the surface of a dry penny.Predict how many drops you think this penny will hold after being smeared with detergent. Group Member #1: _______Group Member #2: _______Group Member #3: _______Draw a diagram showing the shape of the water on the penny after one drop, when the penny is half full and just before it looks like it is going to overflow.After 1 drop: When penny is half full: Just before overflowing:206057520002541109902012950205105Did the detergent have an effect on the outcome?How does the detergent affect the water? (Look back at the definition for surface tension)Explain how detergents act as cleaning agents.Station #3 – Heat of Vaporization and Specific Heat CapacityWhat is heat of vaporization? Which substance in the activity had the higher heat of vaporization?Based on your results explain why water is a much more effective coolant than alcohol for the body. 4. How does this property help water moderate the Earth’s climate?Part 2What is specific heat?Think about what happens when you boil water for pasta. Which becomes hot first, the pot or the water in the pot?Explain why this property of water is important to living organisms. Station #4 - Universal Solvent1. Why is a water a universal solvent?2. What types of substances dissolve in polar solvents? What types of substances do not dissolve in polar solvents? 3. Which substance(s) did not dissolve completely in water? Why?4. Compare and contrast terms polar and non-polar.Station #5 - Density1. How is the density of liquid vs. solid water different than most substances?2. Why does this difference occur?3. What happens when you placed the ice cube in water?4. Explain why this property is important to aquatic organisms. Why would they not survive if water did not have this property?Station #6 - Adhesion1. What is adhesion?2. Describe what happens when you place a straw in a drink or rain drops fall on a window. 3. Relate this phenomenon to the water property of adhesion.4. What organism(s) depend on this property of water? Why?Summary1. List three things that you discovered about water.2. How do the characteristics of water help the body and our planet?3. Review your answers to the questions from Station 1. Which property of water is represented by each question? Explain your answers. 1. 2. 3. 4. 5.6. ................
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