alternative to gas syringe

[periwinkle]

what is a good alternative to a gas syringe, that will mena that gas cannot escape before the bung is put on
many thanks

[brachiopod]

Do you require quantitative analysis? (ie. you need to measure the volume of gas produced)

Or do you just require a sufficient sample of the gas?

If the latter, there are always displacement methods for gas sample collection - downward displacement for denser gases (eg. CO2) or upward displacement for low density gases (eg H2)

For quantitative collection, there is downward displacement of water - an inverted, calibrated vessel (eg. measuring cylinder) filled with water - as the gas bubbles into it, the water is displaced the volume of gas can be measured. NB - this won't be much use for hydrogen chloride or ammonia or any other water-soluble gases.

What are you after?

[lugus]

Under what circumstances are you using the syringe? I work in a lab and take gas samples on an almost daily basis but not using abung anywhere. A bit more info and I might have a suggestion but if you're just collecting then under water, as above.

[periwinkle]

i am seeing how concentration of hydrogen peroxide affects the rate of reaction when is being broken down by catalase. i was measuring the oxygen in a gas syringe as a way of measuring the rate of reaction.
i had to put the blended potato and hydrogen peroxide in a special boiling tubethe put a bung onto seal it. problem is some gas will escape before i can put the bung on so i need some kind of alternative...i have to be able to measure the amount of oxygen made so it s quantititive analysis
hope this makes sense tnx

[lugus]

Then as brachiopod says, collect under water. Side arm conical flask with a delivery tube attached and a thistle funnel through the bung. Put your potato in the flask and add your peroxide through the funnel. Gas will then exit through the delivery tube and displace the water in the measuring cylinder. Time it and you have both rate and quantity. Hope this helps.

[periwinkle]

thankyou loads

[lugus]

Don't mention it.