| time
requ.: |
15 minutes. |
|
objective: |
Build yourself
a low cost device for
generating some ccm of gas |
| material: |
- 2 syringes 10ml
- 1 syringe 5ml (syringe 1)
- activated charcoal
- glass wool
|
- snap top vial ~5ml
- fitting rubber stopper
- 2 needles 1*50mm
|
|
procedure: |
|
filter with activated charcoal |
| |
This gas generator may be assembled by teachers or
experienced students. Most critical operation is pushing the needles
carefully
through the rubber stopper. Syringe 1
contains the liquid reactant (e.g. conc. sulphuric acid), the snap top
vial the solid one (e.g. sodium chloride). Syringe 1 always remains on
top of the needle. With syringe 2 you may extract the gaseous product (e.g.
hydrogen chloride) for further use. Do not remove the needle from the
rubber stopper, remove the syringe only. Use the charcoal filter on the
needle as soon as you remove the syringe. For safety reasons a
charcoal filter is required. Remove the plunger and fill the tube
with a small portion of glass wool, then almost to the top with
activated charcoal, close with glass wool. This device you may use in
the classroom even if the product ist hydrogen chloride or chlorine gas.
The amount obtained is very small (2-10 ccm) and set free in worst case
will be of no harm, because it readily disperses in some cubic meters of
classroom air. Normal use is to apply charcoal filter. |
|
source: |
the late top
experimenter of the german speaking world: Viktor Obendrauf, Austria. |
