Agata Łuszczyńska 23.01.2008

II Lo. im. Stefana Batorego I ib

Investigate the effect of acid rain
on building materials

Design
1 asp
2 asp
3 asp

Design:

The term "acid rain" is commonly used to mean the deposition of acidic components in rain, snow, fog, dew, or dry particles. Distilled water, which contains no carbon dioxide, has a neutral pH of 7. Unpolluted rain is slightly acidic, its pH being about 5.6, because carbon dioxide and water in the air react together to form carbonic acid, a weak acid. The extra acidity in rain comes from the reaction of primary air pollutants (ex. sulfur oxides and nitrogen oxides), with water in the air to form strong acids. Then the rain has pH of 5.4 and lower. Acidic rain has a bad influence on most of the building materials especially marble (CaCO₃) which was and still is used to cover the walls of buildings.

In my investigation I will stuy how much different acids found in acid rain influence the deterioration of marble.

Variables:

Independent:

• type of acid

Dependent:

• amount of dissolved marble

Controlled:

• time for which the acid reacts with the marble (10 min)

• concentration of the acids (1 M)

• temperature (20°C)

Equipment:

• scale ± 0.01g

• beaker

• stoper ± 0.1s

Reagents:

• sulfuric acid (H₂SO₄)

• nitric acid (HNO₃)

• marble (CaCO₃) 10g

In the experiment I will put two 10g pieces of marble into beakers with sulfuric and nitric acid for 10 minutes.

After that time I will take out the marble which was left and weight it. To check how much of it reacted with the acid I will substract the mass after the reaction from the initial 10g.

I will repeat the whole experiment twice to ensure myself with the result.

The best way to collect data will be a table:

Type of acid	Number of trial	Initial mass [g]	Final mass [g]	Reacted mass [g] (initial - final )
Sulfuric acid ()	1	10
		2	10
	Nitric acid ()	1	10
		2	10

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