Australia's Science Forum

I'm wanting to inflate a balloon with hydrogen gas but I'm not getting enough gas to fully inflate the balloon.
I've used plenty of gran zinc & hcl but only a small inflation.(pre stretched the balloon as well)
Can anyone suggest a better way?? Your help would be appreciated.

Hi!

I've just spoken to our resident experts in all things exploding and dangerous and they tell me 6M NaOH and aluminium foil lightly scrunched in a ball and quite a few of them.
Place the alfoil balls in the botton of a conical flask add the NaOH quickly place the prestretched balloon over the neck of the flask and hold on tight. Use the necessary precautions eg gloves googles labcoat.
We did this last year and I inflated 2 balloons with help very easily.
Probably dangerous but it works.
Good Luck
Lorrae

Thanks, this helps me with my science week experiments as well.

In order to produce enpough pressure to inflate the balloon is difficult without being dangerous.
The pressure build up can shatter the glass flask.

Simple way is to try a plastic freezer bag , secured with a rubber band on the end of your delivery tube.( from your H2 generator)
Make sure the freezer bag has no air in it to start with. It is then easy to collect and fills with only gentle pressure .
When full, tie the bag. Attach the bag to the end of a LONG ruler or pole with sticky tape. Using another really long taper in the end of a pole, set the bag alight. Take great care. Fire hazard. Good though!

Just be careful. I just did this and it kind of exploded on me. Too much NaOH and Al foil the reaction was rather large. If i had a really big balloon it would have been oK. But we had a normal size balloon that didnt go onto the conical flask properly. I did it again after, with less Al and NaOH and it went oK.

I've had similar problems generating enough hydrogen gas to fill a balloon. Whatever way you generate the gas, be aware that balloons are porous and some gas will leak through.
Good luck
Karen

One of the teachers here saus Zinc and Sulfuric Acid with a little bit of copper sulfate works well. Only need a small amount of zinc. Blow the balloon up a few times with air first to stretch it out a bit too.
Rosalie

Just dirty the shiny zinc metal with a solution of copper sulfate first. The solution doesn't have to be strong. Have just tested a 0.2M CuSO4 solution and got blackening of the metal. Rinse the metal to get rid of the copper sulfate, dry and then add the acid. Dirty zinc reacts much quicker than shiny zinc.

Lyn.

Thanks to everyone who answered, I tried Lorraes suggestion which worked really well.
Rob.