(CHEMISTRY)
The rock that was used in experiment #1 is not just an ordinary rock because it’s a calcium carbide and was known here in the Philippines as kalburo. When this chemical compound is mixed with water there will be a chemical reaction and it produces acetylene gas. The two anions of carbon, the carbide (C4-) and dicarbide (C22-) ions react with water to produce hydrocarbons. The carbide ion gives methane gas, and the dicarbide ion gives acetylene gas. This video shows the reaction between calcium carbide and water to produce acetylene and calcium hydroxide. Acetylene is combustible, and burns when ignited. Acetylene was discovered in 1836 by Edmund Davy who identified it as a "new carburet of hydrogen". Acetylene gas is colorless and is mainly uses as efficient gas and chemical building blocks and it also has the highest flame temperature of any common hydrocarbon because of its triple-bond structure H-C=C-H. The acetylene gas is very flammable and it produces a burst of flame when it is ignited. Its high flame temperature allows it to be used in a variety of metal working applications like cutting, welding, brazing, and soldering. Acetylene can also produce from the passage of a hydrocarbon through an electric arc, or partial combustion of methane. The chemical reaction from the experiment number 1 is: CaC2 + 2 H2O → C2H2 + Ca(OH)2 . This reaction is the basis of the industrial manufacture of acetylene, and is the major industrial use of calcium carbide. In experiment number 2, the two balls was shown together first inside the sealed plastic glass and when he twisted it the two balls separated away from each other. This experiment explains centrifugal force. Centrifugal force is an apparent force equal and opposite to the centripetal force, drawing and rotating body away from the center of rotation cause by the inertia of the body.