All cats should know about catalysts !!!
Catalysts are substances which make chemical reactions go faster. This is very important if you are trying to make a financial profit out of a chemical reaction. Supposing your company is making battery acid (sulphuric acid): the faster you make the acid the faster you can sell it and the more profit you can make. Your chemical company needs a catalyst.
What you must know about catalysts:
|The catalyst is not used up in the chemical reaction, so it can be used over and over again.|
|The chemical reaction only needs very tiny amounts of the catalyst.|
You should know of an example of a catalyst:
|Manganese dioxide (a black powder) will catalyse the breakdown of hydrogen peroxide.|
|Car exhaust pipes use catalytic converters to get rid of some of the nasty gases from the engines.|
|Some catalysts are very expensive e.g. the platinum in a catalytic converter.|
|The lead in leaded petrol will poison the catalyst in a catalytic converter.|
If you wanted to annoy your parents and your teachers you might consider bleaching your hair with hydrogen peroxide. Instead of having nice black, red, brown or blond hair it would go loose its colour: you would be a “peroxide blonde”. You could get your hairdresser to do it for you; this is probably much safer than trying to do it yourself. Unfortunately your hair grows so the roots will come out in their original colour and you have to go back to the hairdresses to get it bleached again. This means the hairdressers will have to keep some hydrogen peroxide ready for when you come back.
Hydrogen peroxide looks like water but it is not water. It has to be kept in a dark cold place because it slowly turns into water releasing oxygen. Eventually it will not be strong enough to bleach your hair. Hydrogen peroxide does not last so long if you leave it out of the fridge or in the sunlight. The hairdresser’s stock of hydrogen peroxide might last for several months if it was in the darkness in a fridge. However if someone added a pinch of manganese dioxide it would froth up and turn to water in a few minutes. The manganese dioxide has speeded up the breakdown of the hydrogen peroxide.
Enzymes are special cases of catalysts. Biology teachers call them “biological catalysts”.
Now you must make your revision card.
- Write “catalysts” on one side of an index card.
- Write “They speed up chemical reactions without being used up” on the other side.
- You could also put some examples: Manganese dioxide, platinum, enzymes on the second side.
- Add the card to your revision pack now.