[ Secondary Science Instruction ]


What's in the Water?

Activities Using Computer Based Labs with Probes to Acquire Data




Overview/Introduction:

Although water is mainly H2O, normal tap water and natural bodies of water contain other components as well. Water quality is the measurement of these components.

Quality of water is dependent on human activity, natural chemical and geologic processes, and other factors. Drinking water standards regulate the quality of water we drink to keep it safe for human consumption. Pollutants in natural bodies of water affect fish, plants, and microorganisms. See Pollutant Information.

The tests covered in this lesson include temperature, pH, dissolved oxygen, turbidity, nitrate, and phosphate.

Preparation- Collecting Samples

Purpose or Objective:

  1. To make a water sampler and use proper techniques to collect water.

Time Required: one period to make water sampler

Materials, Tools, and Resources Needed:, PVC pipe, 2 1/2 meters (8 foot length), beer or similar type bottle, cork or stopper to fit bottle, string, 3 meters, duct tape, indelible ink markers

  1. Part A: Temperature

  2. Part B: pH

  3. Part C: Dissolved Oxygen

  4. Part D: Turbidity

  5. Part E: Nitrates and Phosphates

Teacher Preparation:

Water can be collected in many locations (See locations in the Greater Los Angeles area). Fresh water from ponds, steams, rivers, and lakes can be compared with distilled water.

Procedure:

  1. Stand the PVC pipe upright.

  2. Securely tape the bottle to the bottom of the pipe with the duct tape so that the bottle bottom is even with the bottom of the pipe.

  3. Tightly fasten the string to the stopper.

  4. Measuring from the top of the bottle, mark the pipe along the following intervals: 2 cm, 10 cm, 50 cm, 100 cm, 200 cm.

  5. When taking a sample, make sure the bottle has been rinsed several times with the water from the test site. Plug the bottle with the stopper. Submerge the pipe to the desired depth. Tug the string to open and fill the bottle.

Techniques for Taking Water Samples:

  1. Always use gloves and goggles in possible polluted sites.

  2. Whenever possible, take sample from the middle of the body of water at about middle depth using a boat or bridge. Collect samples from local bodies of water such as reservoirs, manmade ponds, lakes, or rivers. Collect several liters at each site in order to run all the tests.

  3. Temperature, pH, carbon dioxide, and oxygen content tests should be done as soon as possible at the test site. Keep water samples for test to be done in the laboratory in a cool location.

  4. Retest in a few days especially before and after a rainstorm, or test in a different location along a river or creek.

Student Handouts/ Record Sheets:

  1. Data chart

Assessment:

Write a essay explaining the interelationship of factors such as temperature, pH, dissolved oxygen, nitrates, and phosphates in a lake that might cause a sudden rise in the algal populations and how this might affect the other organisms in the lake.

Grade 9-12

California Science Content Standards

Acids and Bases

5. Acids, bases, and salts are three classes of compounds that form ions in water solutions. As a basis for understanding this concept:

  •  
    		•  Students know the observable properties of acids, bases, and salt solutions.

  •  
    		•  Students know acids are hydrogen-ion-donating and bases are hydrogen-ion-accepting substances.

  •  
    		•  Students know how to use the pH scale to characterize acid and base solutions.

    Solutions

    6. Solutions are homogenous mixtures of two or more substances. As a basis for understanding this concept

  •  
    		•  Students know the definitions of solute and solvent.

  •  
    		•  Students know how to calculate the concentration of a solute in terms of grams per liter, molarity, parts per million, and percent compositions

    Ecology

    6. Stability in an ecosystem is a balance between competing effects. As a basis for understanding this concept:

  •  
    		•  Students know how to analyze changes in an ecosystem resulting from changes in climate, human activity, introduction of nonnative species, or changes in population size.

  •  
    		•  Students know how water, carbon, and nitrogen cycle between abiotic resources and organic matter in the ecoystem and how oxygen cycles through photosynthesis and respiration.

    Investigation and Experimentation

    Scientific progress is made by asking meaningful questions and conducting careful investigations. As a basis for understanding this concept and to address the content in the other four strands, students should develop their own questions and perform investigations. Students will:

    a. select and use appropriate tools and technology (such as computer-linked probes, spreadsheets, and graphing calculators) to perform tests, collect data, analyze relationships, and display data.

    National Education Technology Standards for All Students

    3. Technology productivity tools

    Students use technology tools to enhance learning, increase productivity, and promote creativity.

    Technology research tools

  •  
    		•  Students use technology to locate, evaluate, and collect information from a variety of sources.

  •  
    		•  Students use technology tools to process data and report results.

  •  
    		•  Students evaluate and select new information resources and technological innovations based on the appropriateness to specific tasks.

    Technology problem-solving and decision-making tools

  •  
    		•  Students use technology resources for solving problems and making informed decisions.

  •  
    		•  Students employ technology in the development of strategies for solving problems in the real world.

     

     

     

     

     


    The Integrating Technology into Science Instruction webpages project is partially funded by grants from The Boeing Company and The Ralph M. Parsons Foundation. Integrating Technology into Instruction is a project of Target Science (target@laep.org) and is displayed on the Los Angeles Educational Partnership Learning Exchange. Target Science is an initiative of the Los Angeles Educational Partnership.
    Updated August 2000