G. W. Thiessen and M. Hall
Monmoufh College Monrnouth, Minois
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I
An lm~rovedGlls Generator for ~ l i m e n t a rChemistry ~
A
small-scale adaptation of the Lassieur generator1 has been developed. This generator combines the economy and easy construction of the washbottle type and t,he efficiency and flexibility of the Kipp. I t provides self-controlled evolut,ion of gas from solid and liquid reagents, with reserve gas st.orage capacity. Generat,ion of hydrogen from mossy zinc and acid, and hydrogen sulfide from iron sulfide a,ndacid, are intended uses.
The generator vessel is a wide-mouth bottle. Pieces of upright 5-mm glass tubing of uniform length are fitted tightly into its bottom. Two sections of larger diameter tubing should be in proper location to accommodate the ends of the thistle tube and si~hon. ~-
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'HALL,W. T.,Chem. Abslr., Y O ~ .42, page ~ 4 7 8 ~ .
A heavy layer of glass wool or asbestos is laid over the top of the platform made by the pieces of glass tubing. This forms a stage for the reactive solid and prohibits small pieces of the solid reagent's falling between, or through, the upright tubing. The area below this porous platform serves as a reservoir for the liquid reacent. .. The fijyrc ~~diwrc.s thr uthw f~~r~r~~rrsoftht!nl)))ar:lttI;; :uch :I.: the 1ntv11101 addinr 4 i d or limid renmws. , the gas delivery tube and the siphon for removing spent reagent from the bottom of the bottle. The operation of the generator is simple. The solid reagent is placed on the porous stage. Liquid reagent is poured into the thistle tube and allowed to fill the volun~ein and around the platform tubes to reach a level where it starts reacting with the solid. The gasexit t,ube remains open until air is driven from the system; it is then clamped. The gas pressure builds up until t,he liquid reagent is forced to a level below the solid. This is possible because of the relatively large reservoir of t,he acid in the bott,le, for the level in the container is lowered little while that in the thistle tube rises sufficiently to balance internal pressure. Therefore, a supply of the required gas is available by merely releasing the pinch clamp on the gas exit tube, which allows the liquid to rise to a level where it once again reacts with the solid. Waste products accumulate in the solution a t the bottom of the bottle. The siphon is then started by pinching off the gas exit tube, opening the siphon, and buildiug up gas pressure until acid is forced through this exit. The siphon continues to operate until the majorit,y of the waste is t,aken off. Fresh solid can be introduced through the small stoppered hole as required. The generator is therefore capa.hle of almost coilti~luousoperation. ~
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Volume 38, Number
I , January 1961 / 19
