NICKEL PLATED IN LEATHER CASE 21/- Post Free INSTRUMENT is not ONLY a LINEN TESTER not ONLY a SCREW THREAD TESTER and GAUGE, not only BRINELL IMPRESSION MEASURER, BUT ALL THESE and MANY MORE COMBINED. W. OTTWAY & Co., LTD., ORION WORKS, EALING, W.5. Naval and Military Telescopic Gun Si ghts, Theodolites, Tacheometers, Levels, Finers' Dials, Prismatic Compasses, Helio graphs, Equatorials, Driving Clocks, Micro meters, Coelostats, Transits, Mirrors, Flat s, Naval, Military and Astronomical Telescopes, Prismatic Binoculars, Sextants, et c., eto. Sanitäts Porzellan-Manufaktur-W. HALDENWANGER, SPANDAU, GERMANY. Representative: E. O. Maempel, Finsbury Pavement House, Moorgate Street, London, E.C.2. BERLIN-PORCELAIN HALDENWANGER GRAMMAR OF LOGIC. 100 Questions and Answers on Grammar of Logic or How to Reason Cor rectly, by J. E Roscoe, M.A., Oxon. An invaluable book for all who desire to excel as speakers and who wish to reas convincingly. SALISBURY SQUARE, THE CHEMICAL NEWS, VOL. CXXXII. No. 3446. MERTON HOUSE, SALISBURY SQUARE, TELEPHONES : A COMPACT AND COMPREHENSIVE SERIES OF REACTIONS AND TABLES IN CHEMISTRY. By ROBERT SAXON, B.Sc., F.C.S. (Continued from Page 203.) This is not Theoretically the HCl remains constant, and no oxygen is given off. exactly true, but nearly so. (iii) 2H) 2H : 2C1. 2H. 2(OH (Mn( Mn(OH)2 Electrolysis is the safest way of getting hydroxides without the hindrance of other salts. Concentrated hydrochloric acid asserts itself and attacks Wherever the anode. possible the chloride is formed, where not so the gas chlorine is dissolved by the liquid to saturation point, when it is given off freely. This forms a convenient means of getting and testing chlorine, without the unsatisfactory explanation of the hidden secondary reactions using sulphuric acid, a peroxide or per-salt, and a chloride. Here we have simply HCl and water 2H) 2H: 2(OH): 2H : 2C1 (C( 2C1 Carbon is not attacked by chlorine. However, it seems possible that its superior negative charge, where water is not greatly in predominance, accepts the positive of the anode and starts the "exchange of partners" along the chain. Concentrated hydrobromic acid will yield bromine rapidly, colouring the water, and concentrated hydriodic acid gives iodine. Chlorine, bromine, or iodine may be separated from the rest by heat. Chlorine being a heavy gas will fall into a gas jar and push out the air, bromine is a liquid, and iodine a solid at ordinary temperatures. Much better ways of preparing the gases electro We now understand that we are dealing with a solution, and therefore do not indicate the fact. When confronted with such an arrangement, we take all the substances outside the two electrodes, that is the 2H and the 2C1, and thus arrive at the new compound ionised, of course, namely Mg(OH)2, in ionic notation Mg: 2(OH). As this is insoluble it does not remain ionised, and remembering that we start with a solution but do not indicate the fact, we do indicate the fact that we get an insoluble body by underlining it so thus : (v) 2H) 2H: 2(OH): Mg: 2C1 (C( 2C1 There is no chance of confusion, for the symbols say that we start with a solution, and solid magnesium hydroxide is written Mg(OH)2, therefore the line indicates the ANODIC OXIDATION is used in a good many processes to oxidise the anode. By oxidation we sometimes mean raising the valency of an element such as turning ferrous chloride FeCl into ferric chloride FeCl3. Such is done by making the anode of the element or compound which is to be oxidised. This can be done with water with those metals showing a tendency to form the oxide and not the hydroxide. Here we have a few : i 2H) 2H: 2(OH) (2Ag(Ag2O/HOH (silver anode) vi 2H) 2H: 2(OH) (Pb( PbO/HOH (lead anode) vii 4H) 4H: 4(OH) (Pb( PbO,/2HOH (lead anode) With metals there is always a tendency to form the hydrate. This always happens with the alkali and third group metals. It is noteworthy that the 2nd, 4th, and 6th group metals give the oxide. viii 6H) 6H:6(OH) (Sb( Sb ̧О ̧/зHOH (antimony) ix 6H) 6H: 6(OH) (Bi( Bi2O1/3HOH (bismuth) |