Carbide Cannons & Miners’ Lamps – The Chemistry?

Chemistry, Technology
When I was a kid, a friend showed me what he called an acetylene cannon. Many know it as a carbide cannon. What made it work? It's all a matter of chemistry. Which Carbide? A carbide is a compound in which carbon is bonded to a more electropositive element. Silicon carbide (SiC) and tungsten carbide (WC) are two well-known examples. What carbide do carbide cannons use? Calcium Carbide The answer is calcium carbide. Lime and coke are placed in an electric furnace. The chemical reaction is: CaO + 3 C → CaC2 + CO2↑ What makes calcium oxide so interesting is its bonding. The valence of calcium is +2. Ordinarily, carbon is assigned a valence of 4. Something's strange here... The puzzle is solved if we write the structure of…
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Cement Production Aggravates Carbon Dioxide Levels

Chemistry, Manufacturing
The greenhouse gas, carbon dioxide, has been present in our atmosphere for thousands of years. Although plants consume CO2, the supply is excessive. To label some sources as natural and some as man-made is futile. Here we discuss how producing cement aggravates carbon dioxide levels. To Illustrate Much of mankind spends considerable time in temperatures around the 80 to 100 degree range. If that temperature increased by 30 to 40 degrees, health and welfare would be endangered. Some carbon dioxide is necessary for proper ecosystem function. But as carbon dioxide increases, the planet's welfare is called into question. So what represents the percentage carbon dioxide due to cement production? Limestone to Lime There are many materials containing a limestone (calcium carbonate, CaCO3). While this ingredient is used in producing cement,…
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Important Differences between Lime and Limestone

[caption id="attachment_7743" align="alignright" width="480"] Lime stripes on football field.[/caption] I feel certain everyone has heard, whether in the realm of gardening or in the realm of sports, the words lime and limestone. Perhaps without even consciously thinking of it, these two words have been considered by many to be synonymous. Yet they are by no means synonymous. Lime Lime is used in delineating the zones and yard lines of a football field. Lime is a fine white powder. It is occasionally spread thinly over lawns as well. What is lime chemically speaking? It is calcium oxide, chemical formula CaO. By slaking lime with water, one obtains, naturally, slaked lime! Slaked lime has the chemical formula Ca(OH)2. The slaking of lime is written, in shorthand, CaO + H2O → Ca(OH)2 +…
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