Vernier Software & Technology

# Acid Rain

## Introduction

Acid rain is a topic of much concern in today’s world. As carbon dioxide gas, CO2, dissolves in water droplets of unpolluted air, the following reaction occurs:

${\text{C}}{{\text{O}}_{\text{2}}} + {\text{ }}{{\text{H}}_{\text{2}}}{\text{O}} \leftrightarrow {{\text{H}}_{\text{2}}}{\text{C}}{{\text{O}}_{\text{3}}}$

H2CO3 is a weak acid that causes the rain from unpolluted air to be slightly acidic. This source of “acid rain” is not usually considered to be a pollutant, since it is natural and usually does not alter the pH of rain water very much. Oxides of sulfur dissolve in water droplets to cause more serious problems. Sulfur dioxide dissolves to produce sulfurous acid, H2SO3, by the equation:

${\text{S}}{{\text{O}}_{\text{2}}} + {\text{ }}{{\text{H}}_{\text{2}}}{\text{O}} \leftrightarrow {{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{3}}}$

This source of sulfur dioxide can occur naturally, as from volcanic gases. More often, however, sulfur dioxide is considered a pollutant, since it is a by-product of fossil-fuel combustion.

The acidity of a solution can be expressed using the pH scale, which ranges from 0 to 14. Solutions with a pH above 7 are basic, solutions with pH below 7 are acidic, and a neutral solution has a pH of 7. In Part I of this experiment, you will study how the pH of water changes when CO2 is dissolved in water. In Part II, you will study the effect sulfuric acid has on the pH of different water types.

## Objectives

In this experiment, you will

• Measure pH.
• Study the effect of dissolved CO2 on the pH of distilled water.
• Study the effect on pH of dissolving H2SO4 in various waters.
• Learn why some bodies of water are more vulnerable to acid rain than others.

## Sensors and Equipment

This experiment features the following Vernier sensors and equipment.

### Option 2

You may also need an interface and software for data collection. What do I need for data collection?

## Biology with Vernier

See other experiments from the lab book.

 1 Energy in Food 2 Limitations on Cell Size: Surface Area to Volume 3 Acids and Bases 4 Diffusion through Membranes 5 Conducting Solutions 6A Enzyme Action: Testing Catalase Activity 6B Enzyme Action: Testing Catalase Activity 7 Photosynthesis 8 The Effect of Alcohol on Biological Membranes 9 Biological Membranes 10 Transpiration 11A Cell Respiration (O2) 11B Cell Respiration (CO2) 11C Cell Respiration (Pressure) 11D Cell Respiration (CO2 and O2) 12A Respiration of Sugars by Yeast 12B Sugar Fermentation 13 Population Dynamics 14 Interdependence of Plants and Animals 15 Biodiversity and Ecosystems 16A Effect of Temperature on Respiration 16B Effect of Temperature on Fermentation 17 Aerobic Respiration 18 Acid Rain 19 Dissolved Oxygen in Water 20 Watershed Testing 21 Physical Profile of a Lake 22 Osmosis 23A Effect of Temperature on Cold-Blooded Organisms 23B Effect of Temperature on Cold-Blooded Organisms 24A Lactase Action 24B Lactase Action 25 Primary Productivity 26 Control of Human Respiration 27 Heart Rate and Physical Fitness 28 Monitoring EKG 29 Ventilation and Heart Rate 30 Oxygen Gas and Human Respiration 31A Photosynthesis and Respiration (O2) 31B Photosynthesis and Respiration (CO2) 31C Photosynthesis and Respiration (CO2 and O2)

### Experiment 18 from Biology with Vernier Lab Book

#### Included in the Lab Book

Vernier lab books include word-processing files of the student instructions, essential teacher information, suggested answers, sample data and graphs, and more.