Title: Acid Rain

Problem/Purpose:to simulate the conditions of acid rain in a small-scale model.

Background:Water is a universal solvent. That means, given enough time, water will practically dissolve almost anything. However, sometimes water become a more active solvent, in other words in can start to dissolve things more quickly. Enter the problem of acid rain: Pollutants often enter the air ruin air quality for everyone. These pollutants come mostly from cars, trucks, and certain energy plants. One of the problems with these pollutants is that since there is always some moisture in the air, these pollutants become dissolved in the water that is in the air. The result is that it makes the rain more acidic – more of an acid. Acids have a tendency to be even stronger solvents then just plain water.

Scientist use many type of apparatus to test pH. One type is the use of pH paper. With pH paper, the scientist holds the paper with forceps and dips the pH paper into the solution he is testing. The pH paper will turn color, and then the scientist matches this color change against a color-change chart to determine the pH value.

Hypothesis: If water has more acids in it, then it … will/will not … become a stronger solvent. Q1

Materials:(to be completed by student) Q2

Procedures:

Using pH paper, measure the pH of pure water. Record its value in your data section.
The ph of rain water is usually 5 – 5.6 in pH.
In a beaker of water place a piece of chalk and record your observations carefully.
Fill a second beaker with carbonated water. Measure its pH.
Now place a piece of chalk in the second beaker and record your observations carefully.
Fill a third beaker with Mr. Zimmerman Acid Rain mix (vinegar/water). Measure its pH.
Now place a piece of chalk in the third beaker and record your observations carefully.

Data:

pure water ______pH Q3
rain water ______pH
carbonated water ______pH
Zim’s Mixture______pH

Acid Rain ModelObservations

Rain water______Q4

Carbonated water______

Zim’s Acid Rain Mixture______

Analyze:

Rank the acidity of each substance from least acidic to most acidic. Q5

What happened to our chalk sample as the acidity level increased? Q6

Conclusions:

Since chalk is very similar in chemical compositions to limestone and marble, (which are used widely in commercial construction of buildings, museums and statues), what do you think could be an effect of acid rain on these structures as evidenced by your lab. Q7

Answer our objective and write a paragraph of at least 5 sentences explaining what you learned in this lab. Q8

Complete and hand in the Acid Rain questions from the on-line tutorial which accompanies this lab on Q9-10