Qualitative chemical analysis and laboratory practice / by T.E. Thorpe and M.M. Pattison Muir.

  • Thomas Edward Thorpe
Date:
1894
Catalogue details

Licence: Public Domain Mark

Credit: Qualitative chemical analysis and laboratory practice / by T.E. Thorpe and M.M. Pattison Muir. Source: Wellcome Collection.

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    Fig. i8. gradually invert the bottle as if you were pouring from it on to the taper (fig. i8). The lighted taper soon goes out. This experiment confirms what you have already learned while preparing this gas, viz. that it extinguishes flame, and that it is heavier than air. Experiment IV—Put a small newly- cut piece of sodium, about the size of a pea, into the flask containing carbon dioxide, and gently heat the flask—the sodium melts, and then takes fire; cover the mouth of the flask with the thumb, and agitate it, so as to move the burning sodium about from ])lace to i)lace. When the sodium has ceased to burn, allow the flask to cool, and then pour a little water into it; you notice black .soot-like flakes floating about in the water. 'I’he carbon dioxide has been broken up into its elements by the burning sodium, which has seized upon the oxygen so greedily as to cause evolution of light and heat, while the carbon has been liberated in the free state. Carbon dioxide, in respect of its power of supporting combustion, may be classed with nitric oxide. Experiment V— Pour a little water into the second bottle of carbon dioxide, close the mouth of it with the hand, and shake briskly ; bring the bottle, inverted, under the water of the trough, and withclraAv the hand : the water rises in the jar. Now place the hand as before, and lift the bottle out of the water ; pour into it a few drops of clear lime-water, and shake several times ; you notice that the liquid becomes turbid, which, as you know, is proof of the presence of carbon dioxide. You have therefore dissolved this gas in water. Experiment VI.—Into the third bottle of carbon dio.xide pour a little caustic potash or caustic soda solution, close the mouth of the bottle with the hand, and shake briskly;