ACID RAIN

Learning Goals:

• To understand the what acid rain is and how it is caused

• To understand the interactions between the 4 spheres

• To understand fossil fuels and energy sources• To understand the theory’s of global warming

and climate change.

• Burning coal. Oil and natural gas in power stations makes electricity, giving off sulphur dioxide gas.

• Burning petrol and oil in vehicle engines gives off nitrogen oxides as gases.

• These gases mix with water vapour in the atmosphere producing weak solutions of sulphuric and nitric acids – which fall as acid rain.

CAUSES OF ACID RAIN?

• When CO2 reacts with water, carbonic acid is formed.

CO2 (g)+H2O(l)-H2CO3(aq)

• When SO2 reacts with water, sulfurous acid is formed.

SO2 (g)+H2O(l)-H2SO3(aq)

• When NO2 reacts with water, nitric acid is formed.

2NO2(g)+H2O(l)-HNO2(aq)+HNO3(aq)

MAKING ACID RAIN

• Acid rain can travel long distances.

• Often it doesn’t fall where the gas is produced.

• High chimneys disperse (spread) the gases and winds blow them great distances before they dissolve and fall to Earth as rain.

PROBLEM OF ACID RAIN

In 1750, WITHOUT industry & vehicles, there was around 280 CO2 molecules in every million air molecules

In 2007, WITH industry & vehicles, there is now 380 CO2 molecules in every million air molecules (35% increase)

Plants

Animals

Industry &Vehicles

OrganicMaterial

FossilFuels

Atmosphere

Photosynthesis

Respiration

Decomposition

Burning

Pumping

Plants

Animals

OrganicMaterial

Atmosphere

Respiration

Decomposition

Photosynthesis

FossilFuels

THE CARBON CYCLE

The needles and leaves of the trees turn brown and fall off.

Trees can also suffer from stunted growth; and have damaged bark and leaves, which makes them vulnerable to weather, disease, and insects.

ACID RAIN AFFECTS THE BIOSPHERE

This happens when trees grow in soil that has come into contact with acid rain.

The soil poisons the tree with toxic substances that the rain has deposited into it.

ACID RAIN AFFECTS THE LITHOSPHERE

Acid rain dissolves the stonework and mortar of buildings (especially those made out of sandstone or limestone).It reacts with the minerals in the stone to form a powdery substance that can be washed away by rain.

ACID RAIN AFFECTS THE LITHOSPHERE

• There are numerous ways of stopping these gases from entering our atmosphere.

• These include:• industries adding “scrubbers” to their smoke stacks

to reduce the amount of sulphur released. • Washing the coal before it is burned, which reduces

the amount of sulphur in the coal.• Reducing the amount of car exhaust pollution is done

by fitting catalytic converters to vehicles to make the exhaust fumes less harmful.

HOW CAN WE STOP ACID RAIN?