A Short Manual of Chemistry Volume 1 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1886 Excerpt: ... or explosion; if the interstices between the grains are filled with incombustible materials (such as glass or sand), so as to isolate the grains, the powder is no longer explosive. If the intimately mixed ingredients are reduced to a fine powder, the mixture only burns with greater or less rapidity, but produces no explosion unless confined. Gunpowder explodes at a temperature of about 550 F. (232 C.) The chief effect of gunpowder is due to the combustion of the charcoal by the oxygen of the nitre; the Bulphur is added to increase the inflammability of the mixture. The gaseous products evolved during the explosion of gunpowder (about 43 per cent, by weight of the powder used) are chiefly carbonic anhydride, carbonic oxide, and nitrogen; the solid products (about 57 per cent, of the powder used) consist for the most part of carbonate, sulphate, and sulphide of potassium. One cubic inch of powder yields about 280 cubic inches of gas measured at 0 and 760 mm. Bar., but owing to the high temperature at the moment of explosion (about 4000 F. or 2200 C.) the pressure exerted is equal to about 6400 atmospheres, or some 42 tons to the square inch, if the powder is exploded in a space which it entirely fills; if the powder does not entirely fill the space, or if Buch space be enlarged in consequence of the explosion, the pressure becomes less in proportion. The total amount of work done by the explosion of 1 lb. of gunpowder is equal to 480 /oot-lom; tbat is, by means of the explosion of 1 lb. of gunpowder we could raise 480 tons 1 foot high, or 1 ton 480 feet high. Normal or Neutral Potassium Sulphate, K2SOt = 174-2. S02 (OK)2; K20, SO. Specific gravity, 2-66 water = 1). Melting point, above 861. Properties.--This salt crystallises in transparent, anhydrous, rhomb...