Penny le Couteur & Jay Burreson by Napoleon's Buttons: How 17 Molecules Changed History Page B
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snowâ) is potassium nitrate, chemical formula KNO 3 . The carbon in gunpowder was in the form of wood charcoal and gives the powder its black color.
Gunpowder was initially used for firecrackers and fireworks, but by the middle of the eleventh century flaming objectsâused as weapons and known as fire arrowsâwere launched by gunpowder. In 1067 the Chinese placed the production of sulfur and saltpeter under government control.
We have no certainty as to when gunpowder arrived in Europe. The Franciscan monk Roger Bacon, born in England and educated at Oxford University and the University of Paris, wrote of gunpowder around 1260, a number of years before Marco Poloâs return to Venice with stories of gunpowder in China. Bacon was also a physician and an experimentalist, knowledgeable in the sciences that we would now call astronomy, chemistry, and physics. He was also fluent in Arabic, and it is likely that he learned about gunpowder from a nomadic tribe, the Saracens, who acted as middlemen between the Orient and the West. Bacon must have been aware of the destructive potential of gunpowder, as his description of its composition was in the form of an anagram that had to be deciphered to reveal the ratio: seven parts saltpeter, five parts charcoal, and five parts sulfur. His puzzle remained unsolved for 650 years before finally being decoded by a British army colonel. By then gunpowder had, of course, been in use for centuries.
Present-day gunpowder varies somewhat in composition but contains a larger proportion of saltpeter than Baconâs formulation. The chemical reaction for the explosion of gunpowder can be written as
This chemical equation tells us the ratios of substances reacting and the ratios of the products obtained. The subscript (s) means the substance is a solid, and (g) means it is a gas. You can see from the equation that all the reactants are solids, but eight molecules of gases are formed: three carbon dioxide, three carbon monoxide, and two nitrogens. It is the hot, expanding gases produced from the rapid burning of gunpowder that propel a cannonball or bullet. The solid potassium carbonate and sulfide formed are dispersed as tiny particles, the characteristic dense smoke of exploding gunpowder.
Thought to have been produced somewhere around 1300 to 1325, the first firearm, the firelock, was a tube of iron loaded with gunpowder, which was ignited by the insertion of a heated wire. As more sophisticated firearms developed (the musket, the flintlock, the wheellock), the need for different rates of burning of gunpowder became apparent. Sidearms needed faster-burning powder, rifles a slower-burning powder, and cannons and rockets an even slower burn. A mixture of alcohol and water was used to produce a powder that caked and could be crushed and screened to give fine, medium, and coarse fractions. The finer the powder, the faster the burn, so it was possible to manufacture gunpowder that was appropriate for the various applications. The water used for manufacture was frequently supplied as urine from workers in the gunpowder mill; the urine of a heavy wine drinker was believed to create particularly potent gunpowder. Urine from a clergyman, or better yet a bishop, was also considered to give a superior product.
EXPLOSIVE CHEMISTRY
The production of gases and their consequent fast expansion from the heat of the reaction is the driving force behind explosives. Gases have a much greater volume than do similar amounts of solids or liquids. The destructive power of an explosion is due to the shock wave caused by the very rapid increase in volume as gases form. The shock wave for gunpowder travels around a hundred meters per second, but for âhighâ explosives (TNT or nitroglycerin, for example) it can be up to six thousand meters per second.
All explosive reactions give off large amounts of heat. Such reactions are said to be highly exothermic. The large amounts of heat act
Gunpowder was initially used for firecrackers and fireworks, but by the middle of the eleventh century flaming objectsâused as weapons and known as fire arrowsâwere launched by gunpowder. In 1067 the Chinese placed the production of sulfur and saltpeter under government control.
We have no certainty as to when gunpowder arrived in Europe. The Franciscan monk Roger Bacon, born in England and educated at Oxford University and the University of Paris, wrote of gunpowder around 1260, a number of years before Marco Poloâs return to Venice with stories of gunpowder in China. Bacon was also a physician and an experimentalist, knowledgeable in the sciences that we would now call astronomy, chemistry, and physics. He was also fluent in Arabic, and it is likely that he learned about gunpowder from a nomadic tribe, the Saracens, who acted as middlemen between the Orient and the West. Bacon must have been aware of the destructive potential of gunpowder, as his description of its composition was in the form of an anagram that had to be deciphered to reveal the ratio: seven parts saltpeter, five parts charcoal, and five parts sulfur. His puzzle remained unsolved for 650 years before finally being decoded by a British army colonel. By then gunpowder had, of course, been in use for centuries.
Present-day gunpowder varies somewhat in composition but contains a larger proportion of saltpeter than Baconâs formulation. The chemical reaction for the explosion of gunpowder can be written as
This chemical equation tells us the ratios of substances reacting and the ratios of the products obtained. The subscript (s) means the substance is a solid, and (g) means it is a gas. You can see from the equation that all the reactants are solids, but eight molecules of gases are formed: three carbon dioxide, three carbon monoxide, and two nitrogens. It is the hot, expanding gases produced from the rapid burning of gunpowder that propel a cannonball or bullet. The solid potassium carbonate and sulfide formed are dispersed as tiny particles, the characteristic dense smoke of exploding gunpowder.
Thought to have been produced somewhere around 1300 to 1325, the first firearm, the firelock, was a tube of iron loaded with gunpowder, which was ignited by the insertion of a heated wire. As more sophisticated firearms developed (the musket, the flintlock, the wheellock), the need for different rates of burning of gunpowder became apparent. Sidearms needed faster-burning powder, rifles a slower-burning powder, and cannons and rockets an even slower burn. A mixture of alcohol and water was used to produce a powder that caked and could be crushed and screened to give fine, medium, and coarse fractions. The finer the powder, the faster the burn, so it was possible to manufacture gunpowder that was appropriate for the various applications. The water used for manufacture was frequently supplied as urine from workers in the gunpowder mill; the urine of a heavy wine drinker was believed to create particularly potent gunpowder. Urine from a clergyman, or better yet a bishop, was also considered to give a superior product.
EXPLOSIVE CHEMISTRY
The production of gases and their consequent fast expansion from the heat of the reaction is the driving force behind explosives. Gases have a much greater volume than do similar amounts of solids or liquids. The destructive power of an explosion is due to the shock wave caused by the very rapid increase in volume as gases form. The shock wave for gunpowder travels around a hundred meters per second, but for âhighâ explosives (TNT or nitroglycerin, for example) it can be up to six thousand meters per second.
All explosive reactions give off large amounts of heat. Such reactions are said to be highly exothermic. The large amounts of heat act
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