Revision:GCSE Science OCR C1 Air pollutants

Main air pollutants

The main air pollutants in the atmosphere which are harmful are: sulphur dioxide, carbon monoxide, nitrogen dioxide and carbon/particulates. They are harmful because they cause problems for human beings and the welfare of the planet.

- Sulphur dioxide causes acid rain which can cause erosion and kill certain species in lakes, rivers and other various wildlife.

- Carbon monoxide is a poisonous gas that reacts with blood and if taken in copious amounts can amount to death.

- Nitrogen dioxide, causes again, acid rain however also causes breathing problems and can make asthma worse.

- Lastly, particulates will make things dirty and if breathed in by your lungs can give you a lung infection or make asthma worse.

(Please note that the colours are only to help with memory and do NOT represent colours of the gases as most are colourless)

Getting rid of some of these pollutants

There are different methods of reducing these harmful pollutants in the atmosphere. One of the main contributors to carbon monoxide emissions, was once, cars and engines. Since this, catalytic converters have been designed which turn carbon monoxide into carbon dioxide, equally a pollutant, but ultimately less harmful. In the converter, the carbon monoxide is made to react with another oxygen molecule (CO + O), this results to the product of carbon dioxide.

Notes about the catalytic converter:

- The waste gases pass through a honeycomb structure.

- Honeycomb structures have a large surface area coated by platinum.

(May be worth acknowledging that it is platinum which is un-reactive. Any other elements used could well react with the carbon monoxide forming other undesired elements.)

- The platinum acts as a catalyst also which speeds up the reaction by doesn't use itself up.

Also in the converter... Nitrogen monoxide + carbon monoxide --> nitrogen + carbon dioxide