From: jarmala@pcuf.fi (Ari J{rm{l{)
Newsgroups: rec.pyrotechnics
Subject: Hydrogen/Oxygen bombs with electrolysis
Date: 30 Dec 92 22:34:50 GMT
Organization: The PC-users of Finland


 
Last week I restarted my old hobby: H-bombs. They are very
inexpensive to produce, but rather difficult to transport. This is
how I make them:
 
Equipment
 
  - a transformator producing DC about 6 - 12 V
  - insulated copper wire
  - two lead sheets about 12 x 30 mm, 1 - 3 mm thick
  - erlenmayer flask 50 - 100 ml
  - rubber cap for the flask with two holes
  - glas pipe to fit one of the holes in the cap
  - rubber or plastic flexible pipe to fit to the glas pipe
  - 10 g sodium sulphate (Na SO ) (or sulphuric acid)
                            2  4
  - a piece of paraffin or candle
  - open pot of 2 - 5 liters
 
Construction
 
  Dilute 10 g of sodium sulphate to 100 ml of water. Put the
  solution into the erlenmayer. It is going to be the electrolyte.
 
  Remove 5 mm of the insulation of the wire. Fold this end of the
  wire into a bend piece of lead. Hammer the lead tightly around
  the wire, the copper must not be accessible to any solution.
  Make two of these, they are going to be the electrodes.
 
  Put the 2 wires through one hole in the rubber cap. Seal the
  wires and the hole by soldering them with paraffin. Put the pipe
  through the other hole. Attach the rubber pipe to the (glas)
  pipe.
 
  Make sure that the erlenmayer is nearly full of electrolyte, max
  5 ml air. Close the erlenmayer with the rubber cap (with its
  electrodes). Make sure the electrodes are in the electrolyte and
  well apart from each other (if the elctrodes meet they make a
  spark and the whole setup can explode).
 
Fun (version 1)
 
  Pour 5 cm of water into the pot. Put some detergent into the
  water (the one you use for dishes). Lead the rubber pipe into the
  water at the bottom of the pot and _make sure it stays fully
  immersed all the time_.
 
  Connect the electrodes to the plus and minus contacts of the
  transformer, respectively. If you prepared both electrodes of
  lead, the plus/minus order of the electrodes is insignificant
  (bear in mind that only leaden anode survives, but any metal in
  cathode does well).
 
  You notice that tiny bubbles of gas rise from both electrodes:
  hydrogen at the cathode and oxygen at the anode. The amount of
  hydrogen released is twice the amount of oxygen. Consequently,
  the hydrogen/oxygen gas mixture is always stoichiometric and
  therefore gives most bang for the buck.
 
  Now you have detergent+water in the pot. You should get bubbles
  of gas on the surface of the water. Beware! The gas is
  explosive. Light not more than 2 cm3 of bubbles with a match.
  When you get accustomed with the report you may increase the
  number of bubbles.
 
Fun (version 2)
 
  Change fresh water into the pot (no detergent). Collect
  the gas pneumatically into a water-filled _plastic_ bottle. 0.2
  - 0.5 litre bottles will do in the beginning. When full of gas
  cap the bottle tightly. Tape an ordinary sparkler to the bottle.
  Light the sparkler and run! When the burning region of the
  sparkler reaches the surface of the bottle it (hopefully) melts
  and penetrates the wall and ignites the hydrogen/oxygen gas in
  the bottle.
 
  The report of a 1 - 1.5 litre bottle should equal M-80.
 
  If you create bubbles in the bottle you get a more powerful
  explosion than with plain gas.
 
 
  Try to reduce the consumption of bottles by preparing the
  following device:
 
  - remove the top from a rigid plastic bottle
                                                           fuse
  - collect the gas into this cylinder             foil  ===========
                                                  ------------
  - cover the open end of the cylinder            I|        |I
    with plastic foil _underwater_                I|        |I
                                                  I|        |I
  - secure the foil with a rubber string           |        |
                                                   |        |
  - dry the plastic foil with a cloth              |        |
                                                   |        |
  - tape a fuse onto the plastic foil              | bottle |
                                                   |        |
  - go outside, light the fuse and run             |        |
                                                   |        |
  - re-use the cylinder                            |        |
                                                   |        |
                                                   |________|
 
  A plastic (PVC) or metal tube is also suitable for making the
  cylinder. Inside diameter of about 50 mm and 20 - 25 cm lenght
  is sufficient.
 
 
The science behind
 
  Water is the oxide of hydrogen:
 
  2 H  + O  -> 2 H O  + energy
     2    2       2
 
  With electrolysis you can break the bond in the water molecule
  and separate the elements from water. The amount of electricity
  to do this is 4 farads (=385948 As) per 2 moles (=36 g) of
  water. The reactions are
 
                       -                              -
  on the anode:    4 OH           ->  2 H O + O  + 4 e
                                         2     2
 
                        +      -
  on the cathode:  4 H O  + 4 e   ->  4 H O + 2 H
                      3                  2       2
 
                       -        +
  the total:       4 OH  + 4 H O  ->  6 H O + 2 H  + O
                              3          2       2    2
 
  which is:        2 H O          ->  2 H  + O
                      2                  2    2
 
 
  If you have a transformer giving 2 A current (and enough
  voltage, about 4 V shoud do) you can produce about
 
  2 A x 3600 s/h
  --------------- * 3 mol = 0.056 mol/h = 1.35 litres per hour.
  385948 As
 
 
Enjoy!
 
Standard disclaimers apply.
 
---------------------------------------------
Ari Jarmala (the three 'a's are umlauted),
     o             o
at 60 19'49" N   24 18'38" E
---------------------------------------------
 
Newsgroups: rec.pyrotechnics