Inorganic chemistry : theoretical and practical with an introduction to the principles of chemical analysis an elementary text-book / by William Jago.

  • William Jago
Date:
1892
Catalogue details

Licence: Public Domain Mark

Credit: Inorganic chemistry : theoretical and practical with an introduction to the principles of chemical analysis an elementary text-book / by William Jago. Source: Wellcome Collection.

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    apparatus. Take out the taper, light, and quickly replace it ; allow it to burn for three or four minutes, then turn off the cock the taper goes out; disconnect the tubing from the top cork and again weigh ; the weight has increased, owing to oxygen laving been taken up from the atmosphere by the burning taper ; it has combined with its constituents to form water and carbon dioxide respectively. These compounds are both aDsoroed and retained by the caustic soda. The apparatus is shown in 1 ig. i. The student, working in a laboratory, will pro- bably find these pieces of apparatus already prepared ready for use. As there is not likely to be a sufficient number for each student to tiy the experiment at the same time, it must be taken in turns. So far from the burning of a candle being accompanied by any loss of its constituents, the weight of the resultant products is greater than that of the candle itself, because they contain in addition the oxygen removed from the atmosphere. Matter being indestructible, it follows that when chemical combination occurs between sub- stances, the weight of the products is exactly the same as that of the bodies previous to chemical action. Proof of this statement will be afforded by experi- ments described in later chapters. 5. Distinction between Mechanical Mixture and Chemical Union.— The student who has carefully performed the preceding experiments will scarcely need to be told that chemical combination is widely different from mere mixture. In the latter case the resultant body is a mean in appearance, specific gravity, dire., between its constituents : they still each possess their individual properties, and the separate particles may be seen with sufficient magnifying power. Experiment 5.—Take some finely divided copper; notice its colour; mix intimately with powdered sulphur; the mixture has a tint intermediate to that of the substances when separate. Place some of the mixed powder in an evaporating basin, and
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