Monday 4 March 2013

Science: Suffocating gases

Suffocating gases!

I did this one at our Home Education Science Group and it was a hit.  Here's how to do it if you fancy a go...

 To do this experiment you will need:

·         a funnel
·         a bottle
·         baking soda
·         vinegar
·         non-hardening modelling clay
·         a pencil
·         long straw
·         one tall and one short candle
·         large jar, fish tank or a waste paper bin
·         matches or a lighter

How to do this experiment:


Get your modelling clay ready.  You will need to put it on top of the jar with the straw coming out like this…

It is easier to do this before you start to make sure there are no gaps for the gas to escape through and to make sure you have enough modelling clay to seal the neck of the bottle.  Take the modelling clay off keeping the straw in position like this…


When you have done that get you get your big candle and small candle and place them in your large container.  Light them both.

With a funnel add 20ml of baking powder then 100ml of white vinegar and as quickly as you can attach the modelling clay with the straw in it.  This should force the CO2 in the bottle to go through the straw.  Direct the straw towards the little candle and watch…

What happened?

The flame of the small candle should have gone out. 

Volcanoes often give out the gas Carbon dioxide (CO2).  CO2 is denser (heavier per cubit cm) than air so when a volcano releases this gas it descends pushing air out of the way.  Carbon dioxide kills people and animals. 

It suffocates them because the cloud of CO2 pushes all the air that people need to breathe to stay alive too far out of reach.  Like we need oxygen to breathe, which is in the air, flames need oxygen to burn. 

What happens in this experiment is that the carbon dioxide that is in the bottle seeps of out the straw and because it is denser that the air it falls on to the flame pushing the oxygen out of the way and extinguishing the flame the same way a volcano can suffocate people and animals.

If you liked this and would like to try the other science experiments go to my Physics page, Chemistry page or Biology page.

No comments:

Post a Comment