Palit, Santi R

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782 Letters to the EditorFor fresh samples the temperature variation of field independent susceptibi­lities both along the r>axis'and in the basal plane agree well with the findings of Tasaki and lida (1963) on syntlu'tio hematite, but there the ferromagnetism, unlike ours, appears only along the plane above Morin temperature (~250'^K) and at lower temperatures no ferromagnetism exists at all in either of the direc­tions. In respect of the tempei ature variations of both the susceptibilities and the fiuToinagnotisrn in the plane, the present obs(Tvations resemble those? of Ne< J et al (1952) and Lin (1959), on very pure natural crystals, but differ with their observations of fcrromagntd-isni along tlie c-axis. Lin (1959) observed consider­able ferromagnetism along the axis below th<‘ Morin temperatun* (~250®K) which falls sharply to a low value at liiglier ti niperatures. Neel cf al., (1952) no doubi observed consi(hu*able ferromn.gri<dism at Jowcu* f<un]H‘ratures (belov'~250''K) but its temperature variation unlike tlu' observation of Lin (1959) was ratlui slow. In onr case on the eontrary the ferromagned-ism a^ong the c-ax s vanislu s beloM' ~25()^K and appears rather sharply abovt* this temperature.The measurements on l)eat treated samples agree closely with those of Milker j(‘c(1967), the magnitude of magnetisat ion and snseeptibilitv increasing eonsiderahlx and the sharp changes at ~250^K vanishing altogether.The author is thankful to Shri A. K. Dutta for his constant guidance and Professor A. Bose for his kind interest in the work.R K F K Ji K NT C FSLin, S. T., 1959, Phys. Pev., 116, 1447.Mukerjee, A. K., 1967, Indian •/. Phys., 41, 466.N6el, L. and Pauthenet, R., 1952, Compt. Pend. 234, 2172.Tasaki, A. and Ii<la, S,, 196,3 J. Phys. Soc. Japan. 18, 1148,26A SIM PLE EXPERIM ENTAL DEM ONSTRATION OF THE BREAKDOWN OF FARADAY’S LAW OF ELECTROLYSISSANTl R. PALITDepartment of Physicai. CJhkmistry, Indian association fob the Citetivation OF Science, J adavpub, Cai,cutta-32, India.The author adduced experimental evidence (Palit, 1967) indicating wifie deviation from Faraday’s law in the electrolysis of weakly conducting solutions, particularly conductivity water. Since this fact runs counter to a long accepted idea, the author presents here a simple experimental device which conclusively demonstrates the failure of Faraday’s law.LcttcTs to the EditoT 783Experimental-^-Thii experimental arrangement is showji in hg 1 o f two conical flasks one contains a 0.5N potassium sulphat(‘ solution whi •! * ] * ri irooominendcd as a eoiilomotrie s(»lntion l>y l i^ngaiH* (1045); the other contains con(iuotivity water. Each flask is provided with two ])latiimm electrode's (I cm < 0.5 cm) and the two flasks ar(' eomiected in serif's. With tin* three-way stopcock open to the atmoaphen', a current of about oiu* to two railliamperes is passed by applying tht* D .(l mains voltagf' (230 volts). This is (jontiinied for a few hours until the two solutions bf^come saturated with eU'ctrolytie gas. Tin* stopcock is then closed so tha t the gases do not ('scaj)e to the atmosphere but collect on the oppoKsite sides of th(‘> manometer. If Parady’s law is valid, (upial cpiantities of gas would g(d. collected on both sidf s^. Since tin' two empty spaces are approxi­mately of (‘.qual volume, the manometer would tliertTore show hardly any diller- erice of pressure with ])rogress of electrolysis. However, if the author’s idea tlmt Faraday’s Jaw is not valid and predominantly non-eloctrolvtic conduction takes place in the electrolysis of water, is correct, the maiiometf'r would indicate in­creasing pressure in the coulometer (potassium sulphate solution) side A^ nth pro­gress of electrolysis.Experimentally, using a small ('inpty space iji each flask it is observed that ^ difference of level is increasingly produced with progress of ehict-rolysis, the coulometer side building up the higher pressure. This convincingly demonstrates the breakdown of Faraday’s law in the electrolysis of water. The demojistration can be repeated again and again by releasing and equalising tlio pressures on both sides of the manometer by proper turning of the three-way stopcock followed by closing the stopcock. With our set-up the rate of production of level difference is observed to be about th irty  mm per lioiir for 2 milliampero current. This on conversion to volume taking into account the dimension of the apparatus means that barely one-third of the Faradaic value of the eleptrolytic gas is liberated784 Letters to the Editoroil electrolysis of pure water. Th(i fact that an appreciable difference in level can b(^  demonstrated in less than half an hour makes this simple experiment a gn^ai success as a lecture demonstration. In addition to the above differential measureinetit which very convincingly demonstrates the failure of Faraday’s law this apparatus is also very suitable by connecting on(‘ side of the manometer to the atmosphere for measuring th(' rate of gas evolution singly in any one of the colls.Our above observations contirm our previous finding that Faraday’s law falls short considerably in th<^  electrolysis of water. Such wide discrepancy is difficult to be explained by assuming side reactions, for example, by assuming / / 2O2 mation at anode and reduction of th() same at cathod(>, as suggested by Page and Lingane (1057) to bf' rosponsibl(' for small observed deficit in hydrogen oxygen gas coulomc^tor. It appears that with decreast^ of ionic concentration and current strength, and increase of voltage, the current tends to be carried by a mechatiisni different from that envisaged by Faraday’s law. As to the mechanism of this lion-electrolytic conduction, it is recalled that in some crystals as also in solutions of sodium in liquid ammonia partly ionic and partly electronic conduction simul­taneously takes plac(‘. In w^ at<'r medium the elf^ctivmic conduction is more liktdy to bo through th(^  interimxliacy of charged wat(*r molecules, andparticularly as hydrated oh'ctron has booji shown to ('xist duiMiig ek^ctrolysis of sodium sulphate solution by Walker (1900, 1907). However, w(' prefer to th(' question of d<^ taih^ d mechanism open until niort*, definite* evidence is lorth- coming. Detailed n'sults with this apparatus will ht* publislu^d later.Thanks are due to Sri Prithwish Kumar Basu for exptuimental assistauce*.K E F E R E N C E SLingani*, J. »!., i945, J. Amr.r. Chen Soc.^ 67, 1910.Page, tf. A. and Lingane, J. .1,, 1957, Anal. Chem. Acta, 16, 175.Palit, S. R., 1967, Indian J . Phys., 41, 309.Walker, D. C., 1966, Ganad. J .  Chem, 44, 2226.-------- , 1967, Quart. Rev., 21, 83.27A NOTE ON LONGITUDINAL DISTURBANCES IN A SEMI-INFINITE PIEZOELECTRIC ROD IN A MAGNETIC f ie l dD. K. SINHAJ>KPARTM£JNT OF MATHEMATICS, JaDAVPUH UnIVEKSITV, CaLCUTTA-3 2 , IKDIA.(Received December 6 , 1 9 6 7 )The piezoelectric problems constitute an import*nt branch of study in view of their applications in ultrasonics and acoustics and these problems have been

A Simple Experimental Demonstration of the Breakdown of Faraday’s Law of Electrolysis

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A Simple Experimental Demonstration of the Breakdown of Faraday’s Law of Electrolysis

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