A college text-book of chemistry . cal language the fact thatwhen 2 grams of hydrogen combine with grams ofoxygen x calories of heat are evolved. The determination is made by burning a known weightof hydrogen in a vessel surrounded by water and arrangedin such a way that all the heat is absorbed by the has shown that when 1 gram of hydrogen isburned 34,180 calories are evolved. Or, [H2, 0] = 68,360 cal. So other substance gives as much heat as this in propor-tion to the weight used. Applications of the Heat formed by the Combination ofHydrogen and Oxygen.—To burn hydroge
A college text-book of chemistry . cal language the fact thatwhen 2 grams of hydrogen combine with grams ofoxygen x calories of heat are evolved. The determination is made by burning a known weightof hydrogen in a vessel surrounded by water and arrangedin such a way that all the heat is absorbed by the has shown that when 1 gram of hydrogen isburned 34,180 calories are evolved. Or, [H2, 0] = 68,360 cal. So other substance gives as much heat as this in propor-tion to the weight used. Applications of the Heat formed by the Combination ofHydrogen and Oxygen.—To burn hydrogen in the air is,as we have seen, a simple matter, but to burn it in oxygenrequires a special apparatus to prevent the mixing of thegases before they reach the end of the the com-bustion takes place. The oxyhydrogen bloivpipe answers 78 COLLEGE CHEMISTRY. this purpose. This may be constructed in several ways,but the simplest is that represented in Fig. 25. It con-sists of a tube through which a smaller tube passes. The. Fio. 25, hydrogen is admitted through a and the oxygen through will be seen that they come together only at the end ofthe tube. The hydrogen is first passed through andlighted; then the oxygen is passed through slowly, thepressure being increased until the flame appears thin andstraight. It gives very little light but is intensely wire, steel, capper, zinc, and other metals burn in theflame with ease. Platinum vessels are made by meltingthe platinum by means of the oxyhydrogen flame. Oxyhydrogen Light.—When the oxyhydrogen flame isallowed to play upon some substance which it cannot meltor burn, the substance becomes heated so high that it givesoff an intense light. The substance commonly used forthis purpose is lime. Hence the light is often called thelime light. It is also known as the Drummond light. The hydrogen is first allowed to pass through the stop-cock, and lighted, when the oxygen is admitted. Theflame plays against the piec
Size: 2914px × 858px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectchemistry, bookyear19
