Some wonderful demonstrations using an inexpensive pressure pump

Available for about €20 from

I’m thinking of getting about 8 to act as a class set, and a few more for presents to nephews and nieces.

The ‘Presssure and Sound’ demo can be done with mobile phones as I suggest – the sound level does drop noticealbly in the classroom, but not enough to be picked up by the camcorder.

I presume it would also go down well on Open Day.

Limitless potential.
Eoghan in Second Year suggested using coke to see if it goes flat – I won’t tell you the answer but it’s worth checking out. In hindsight we should have tried to guess what we would have observed.

Then we wondered if the pH would change.

Then we wondered if the level of Carbon Dioxide in the chamber would increase noticealby, even as we pumped out the air. I need to see if we can use a datalogger to see how the  concentration of the gas changes in real time on a laptop.

Then I mentioned that we need to buy lots of marshmallows to see which work the best.

Then Robyn said that she cooks marshmallows at home, so now she has promised to bring in the ingredients and we will try to cook them in school and see if we can make giant ones!

All for €20 plus the price of few marshmallows, balloons and shaving foam.


Pressure and Boiling Point

I’m in the middle of writing of up reports (who isn’t?) and don’t have a lot of free time, but a couple of times this week I have tried to get the Pressure and Boiling Point demonstration up and running. I figure that as a so-called experienced teacher I should be able to work this without too much trouble. After all it is in all Junior Cert text-books and presumably is on the syllabus – the implication is that every teacher does this.

 I set it up with a partial vacuum caused by running water (how many people use this as a wonderful way of teaching about particle motion?).

I set it up with an electric vacuum pump.

I have put hours into this.

If water could laugh mine would be wearing a smile from cheek to cheek. I imagine I am not forming a sufficient seal, but don’t know how to improve it.

So I resort to youtube. Don’t tell me using the internet to show demonstrations is the lazy option. I try, I really do. I just don’t have green fingers when it comes to this sort of thing.
The worst part of all this is that I now have to go back to Mr O’ Boyle and ask him to show me again how he does it.
And he’s a Chemistry teacher – oh the shame!

Now while checking that this link still works I came across this beauty – off to try it again tomorrow.