GCSE CHEMISTRY - Pollution from Petrol and Diesel Engines - How can Pollution from Vehicle Exhausts be Reduced? - Nitrogen Oxides contribute to Acid Rain

gcsescience.com 91 gcsescience.com

How does Oil affect the Environment? - Transport.

The High Temperature Combustion of Fossil Fuels.

The high temperature combustion of fuel
(in petrol and diesel engines used in cars and lorries)
produces toxic gases in addition to carbon dioxide.

High temperature combustion of fossil fuels causes
nitrogen in the air to react with oxygen producing toxic gases.

nitrogen + oxygen nitrogen monoxide.
N₂_(g) + O_2(g) 2NO_(g)

As well as being poisonous, nitrogen monoxide is a
greenhouse gas. It reacts with oxygen in the air to
form nitrogen dioxide (NO₂).
NO and NO₂ together are called NOx.
NO also reacts with water and oxygen in the air to
form dilute nitric acid. This contributes to acid rain.

Other Pollution from Vehicle Exhausts.

Petrol and diesel fuels contain sulfur and this releases
sulfur dioxide into the air from vehicle exhausts.
Petrol and diesel engines also produce poisonous
carbon monoxide and release unburnt hydrocarbons.

How can Pollution from Vehicle Exhausts be Reduced?

All of the pollution from vehicle exhausts is produced
at ground level, mainly in cities where road vehicles gather.
The obvious solution is to fit road vehicles with
electric motors rather than petrol or diesel engines.
This process is slowly happening but the number
of electric vehicles on the road is still relatively small.

Other ways of reducing pollution from vehicle exhausts
include using low sulfur fuels, fitting vehicles with
catalytic converters, making more efficient engines,
using more public transport and
checking the level of exhaust emissions in MOT tests.