Creating Acetylene Gas
The purpose of the lab was to determine the ratio of air to acetylene results in complete combustion of acetylene gas. The balanced chemical equation for this experiment was C2H2(g) + O2(g) --> CO2(g)+ H2O(l). Complete combustion is the reaction of an element or compound with oxygen to produce the most common oxides and energy. Complete combustion occurs when the fuel and oxygen combine in exact proportions to completely burn the fuel, which leaves a clean test tube. Incomplete combustion is the reaction of an element or compound with oxygen to produce some oxides with less oxygen than the most common oxides. Incomplete combustion occurs when there is not enough oxygen to react completely, not all fuel is used. This may result in the formation of solid carbon a black residue.
The lab was performed on 25 October 2012, the lab results obtained from Ms. Reynold's. Safety precautions were to not breath in the acetylene gas.
Part A: Creating Acetylene Gas
A 600 ml beaker was approximately half filled with water. A test tube was completely filled with water. Test tube was covered with thumb and was turned upside down under water in the beaker. Tweezers were used to drop one piece of calcium carbide into the beaker and was quickly covered with the test tube to collect any gas produced. When the test tube was half full of gas, the test tube was lifted out of the water and the inverted test tube was set on the lab bench. The procedure was repeated for 1/3 gas, 1/4 gas and 1/8 gas.
Part B: Combustion of Acetylene Gas
The test tube was placed upright in the test tube rack and a flaming splint was held at the mouth of the test tube. Observations were recorded. The procedure was repeated for remaining test tubes.
For the test tube with the ratio of acetylene to air is 1:1, a flame traveled down a test tube, a slight pop and black residue was left...