Acid rain project

1. Acid Rain
Chemistry Project
Name: Charu Bhati
Class:9
Section: F

2. What is acid rain
 Acid Rain is when gases in the atmosphere combines with falling water to form acids, which fall as
rain.
 It describes any form of precipitation that contains high levels of nitric and sulfuric acids.
 It can also occur in the form of snow, fog, and tiny bits of dry material that settle to Earth.
 Normal rain is slightly acidic, with a pH of 5.6, while acid rain generally has a pH between 4.2 and
4.4 .

3. Effects of acid rain
 Dead or dying trees are a common sight in areas effected by acid rain. Acid rain leaches aluminum
from the soil.
 That aluminum may be harmful to plants as well as animals. Acid rain also removes minerals and
nutrients from the soil that trees need to grow.
 Dust particles can become acidic as well, and this is called dry deposition.
 When acid rain and dry acidic particles fall to earth, the nitric and sulfuric acid that make the
particles acidic can land on statues, buildings, and other manmade structures, and damage their
surfaces.

4. Formation of acid rain
 Natural sources – bacterial decomposition, forest fires ,volcanic eruptions &
 Man made sources – power, industrial & smelting plants and automobile exhausts ,produce –
oxides of sulphur and nitrogen – which interact with water vapour in the presence of sunlight in the
atmosphere to form – sulphuric acid[H₂SO₄] & nitric acid [HNO₃] mist.
 The mist remains as vapours at high temperatures & condenses at low temperatures The acids mix
with rain [or snow, fog etc] & fall down on the earth resulting in ‘acid rain’

5. Causes of acid rain
 Fossil fuels – are derived from the organic remains of plants & animals .
 Bacterial decomposition of organic matter - releases H₂S which is oxidised to SO₂ .
 Smelting plants – produce SO₂ when metallic sulphides are roasted in air.
 Sulphuric acid plants – produce SO₂ during production of sulphuric acid.

6. Impacts of acid rain
 Causes nutrient leaching.
 Changes the acidity of soil.
 Affects soil fertility.
 Affects marine organisms.
 Changes the pH of the environment.
 Affects transpiration in plants.
 Since the food is acidic the toxicity enters the food chain affecting the humans.
 Material damage.

7. Controlling the acid rain
Reduce amount of Sulphur dioxide and oxides of nitrogen
released into the atmosphere
Use cleaner fuels
Flue Gas Desulphurisation (FGD)
Use other sources of electricity (i.e. nuclear power, hydro-
electricity, wind energy, geothermal energy, and solar
energy)
Reducing the effects of Acid Rain by Liming

8. Thank you