The outlines of physics: an elementary text-book . s way is calleda voltameter. 279. The Water Voltameter. — An instrument designedfor the measurement of current, by means of the amount ofwater which it decomposes, is called a water the decomposition of water by the current, hydrogenplays the part of a metal, and oxygenthat of the acid radical. If, therefore,two platinum electrodes, like thosedescribed in the foregoing experi-ments, be inserted in a dish of water,which should be slightly acidulatedto increase its conductivity, and ifinverted tubes, closed at one end andfilled wit
The outlines of physics: an elementary text-book . s way is calleda voltameter. 279. The Water Voltameter. — An instrument designedfor the measurement of current, by means of the amount ofwater which it decomposes, is called a water the decomposition of water by the current, hydrogenplays the part of a metal, and oxygenthat of the acid radical. If, therefore,two platinum electrodes, like thosedescribed in the foregoing experi-ments, be inserted in a dish of water,which should be slightly acidulatedto increase its conductivity, and ifinverted tubes, closed at one end andfilled with water, be placed over eachelectrode, as shown in Fig. 276, thecurrent sent through the cell will liberate hydrogen gasat the surface of the kathode, which will rise and displacethe water in the tube placed over that electrode, whileqxygen will similarly be collected in the other volume of hydrogen thus produced will be twice asgreat as that of the oxygen, and each of them will beproportional to the time and to the average strength of. Fig. 276. 312 THE OUTLINES OF PHYSICS the current. If we know how many cubic centimeters ofhydrogen a unit of current is capable of producing in onesecond of time, we can tell, from the volume of hydrogenproduced in the water voltameter in a given time, howstrong the current has been. The water voltameter doesnot give accurate results, excepting when very great pre-cautions are taken, on account of the absorption of thegas by the liquid within which they are generated, andthe occlusion, especially of hydrogen, at the surface of theplatinum electrode. Two forms of voltameters, with which it is possible toobtain much better results, are the copper voltameter andthe silver voltameter. 280. Experiment 89. — The Heasurement of Cunent by Means ofa Copper Voltameter. Apparatus : (1) A copper voltameter. The form of voltameter, by means ofwhich an accurate result may most easily be obtained, is constructedas follows: Take four pieces of nak
Size: 1468px × 1702px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, bookpublishe, booksubjectphysics
