Experiments With Acid Precipitation

Acid rain results when rain water contains higher than normal acidic pH levels. Sulfur dioxide and nitrogen oxide get released from factories and automobile fuel combustion, then react with oxygen and water in the atmosphere to manufacture additional pollutants. Acid rain can be wet in deposition, like in the form of rain, sleet, fog and snow. Dry deposition acid rain happens when dust particles and gases become more acidic than usual. Experiments can reveal how acid rain affects our environment.

Water in Nature

• Go to a nearby lake or pond and dip a clean, unused paper cup into the water. Fill the cup with surface water, not water from the bottom near the sediments. Take the sample home. Use some common pH paper, or used a garden soil pH kit, to dip a piece of test paper into the sample. Match the sample to the color chart listing and record the acidic measurement. This experiment will demonstrate that even seemingly clean and unaffected water will contain some amount of acid. Take a sample of water near a factory and record the results. Compare the two readings based on their locations.

Acid Rain and Plants

• Gather four small potted plants of the same species and place each plant in a plastic pot containing soil from the same source. Mark two plants "water" and the other two plants "vinegar." Add 4 1/2 tsp. of white vinegar to a separate container that holds two cups of distilled water, and stir well. Water the "vinegar" plants with 1/8 cup of the vinegar water. Water the "water" plants with 1/8 cup of distilled water. Repeat the watering in the same fashion over a period of five days and watch the growth reaction. The vinegar plants containing acid will whither, lose their color and appear lifeless on the fifth day.

Acid Soil Content

• Add 1 tsp. of white vinegar to a plastic cup containing 2 cups of distilled water. Stir. Check it with pH paper. The measurement should read about 4 on the scale. Place a coffee filter into a funnel, and add soil to it from one location. Sit the funnel over an open paper cup and pour your vinegar mixture over it, letting it drain into the paper cup. Check the pH value of the strained soil water with a pH strip and record the number. Perform the same experiment, using soil from another area and record the results. Both samples will vary according to the acid content in the soil from one location to another.

Acid Effects on Metal

• Label one tall empty glass "water." Label another empty glass "lemon juice." Place a penny in the bottom of each glass, but use pennies minted before 1983, since they contain 97 percent copper but afterward contained mostly zinc. Pour enough lemon juice into one glass to barely cover the top of the penny. Pour water in the other glass, just covering the top of the penny. Dip a pH strip into the distilled water glass. If it reads below 6, add a pinch of baking soda until it reads between 6 and 7. Seal both glasses with plastic wrap and let them set for five days. Examine the bluish-green water in the lemon juice glass and lack of change in the water glass. This experiment shows the corrosive effect acid has on metal.