Acid Rain Lab

 

 

 

Collaborator

Habib Fofana

 

Introduction

Acid rain is a rain or any other form of precipitation that is unusually acidic, meaning that it possesses elevated levels of hydrogen ions (low pH). It can have harmful effects on plants, aquatic animals and infrastructure. Acid rain is caused by emissions of sulfur dioxide and nitrogen oxide, which react with the water molecules in the atmosphere to produce acids. Wet deposition and dry deposition are two types of acid deposition. Wet deposition comes in the form of rain, sleet, hail and snow and dry deposition comes in the form of gases and dust. Wet and dry deposition can be carried long distance by wind currents (EPA.gov). Acid deposition can be inhaled by humans causing respiratory problems. Clear rain can have a pH between 5 to 5.5 but when sulfur dioxide and nitrogen oxides -produced from power plants and automobiles-the rain becomes more acidic. Acid rain tends to have a pH of 4. Major health concerns that can arise from exposure to acid rain are increase disturbance ofasthma and bronchitis. Not only does acid rain pose health threats but also environmental threats such as ground level ozone caused by nitrogen oxides. The chemicals in acid rain can cause paint to peel, corrosion of steel structures such as bridges, and erosion of stone statues.

 

Problem 

How does acid rain affect the growth of fescue plants?

 

Hypothesis 

If the acid rain has a high acidic level of 4, then acid rain will be detrimental to the growth of the grass because high levels of acid can deplete nutrient levels and wash away essential minerals needed for plant growth. 

 

Materials 

9 2 liter bottles containing fescue plants(in this case grass)
water 
white vinegar 
sunlight 

 

Procedure 

Procedure:

• Pour 1 teaspoon of vinegar into 2 cups of distilled water, stir well, and check the pH with either pH paper or a garden soil pH testing kit. The pH of the vinegar/water mixture should be about 4.

• If it is below pH 4, add a sprinkle of baking soda, or a drop of ammonia, stir well, and recheck the pH.

• If it is above pH 4, add a drop or two of vinegar and again recheck the pH.

• Measure the pH of the distilled water using either pH paper.

• Create a second pH solution of your choice. Record the pH of this solution.

• If the pH is below 7, add about 1/8 teaspoon baking soda, or a drop of ammonia, stir well, and check the pH of the water with the pH indicator.

• If the water is still acidic, repeat the process until pH 7 is reached. Should you accidentally add too much baking soda or ammonia, either start over again or add a drop or two of vinegar, stir, and recheck the pH.

• Each group will be responsible for watering 2 plants one day a week according to their

Blue plants: 50 mL of water only

Yellow plants: 50 mL of solution 1

Pink plants: 50 mL of solution 2

 

 

Data 

 

 

Data Analysis 

The grass that had the pH of 2 began to die off immediately in the first week. First it turned yellow then the soil started to lose it's health and finally in week 3, the grass began to lose length. This is comparitively worse then the grass with the pH of 4 who started to die off in the 2nd week instead. The grass with the pH of 5 continued to thrive even through the thrid week. It wasn't hardly effected. 

 

Conclusion 

The hypothesis stated that the grass would start to deteriorate at a pH of 4.The hypothesis was correct. It seemed that a pH of 4-2 is serverly detrimental to the health of grass. A pH of 5 is probably around the normal pH of rain water and it's not acidic enough to cause harm. This means in real life, if we manage to pollut the water enough to drop the pH one more level then farming would be difficult, statues would begin to corrode and we could have wide scale respiratory problems. What we need to do is control the emissions of automobiles and power plants, so that the level of sulfur and nitroge oxides will decrease. Sources of error in this lab could be not doing enoug observations during the week.

 

Citation 

"What Is Acid Rain?" EPA. Environmental Protection Agency, n.d. Web. 08 Jan. 2015.