Method Invert a test tube full of water into a beaker of water, making sure that no water r4uns out of the test tube. Use the tweezers or scoopula to place a few small pieces of calcium carbide into the beaker. Observe the bubbles rising from the calcium carbide. These bubbles are ethyne gas. Place the inverted test tube over the calcium carbide and completely fill the test tube with ethyne gas. Remove the test tube from the water and place it mouth down on the lab bench so that the gas does not escape. Repeat step 3 three more times with the other test tubes this time filling ½, 1/3 and 1/12 of the test tube with acetylene, respectively. Lift each tube from the water, always keeping them inverted. Allow air to replace the water that urns out of the test tubes. Place you8r thumb over the end of each test tube and shake each tube for 20 seconds to mix the air and ethyne. Place each test tube mouth down on the lab bench. One at a time, hold each test tube horizontally and bring a burning splint close to its mouth. Wait until each reaction is complete and then place the test tube back down on the lab bench. Observe each test tube carefully and complete the observation table. Observations Table 1: (9 marks, C) Sample Amount of Observations Diagram of Observations Ethyne / Air after Gas Test 1 1/1 2 1/2 3 1/3 4 1/12 Discussion Questions Write the BALANCED, including the states, chemical reaction for the production of ethyne, C2H2 , from CaC2 and water. (2 marks, I) What did you observe as the amount of oxygen in each test tube increased? (1 mark, I)
Method Invert a test tube full of water into a beaker of water, making sure that no water r4uns out of the test tube. Use the tweezers or scoopula to place a few small pieces of calcium carbide into the beaker. Observe the bubbles rising from the calcium carbide. These bubbles are ethyne gas. Place the inverted test tube over the calcium carbide and completely fill the test tube with ethyne gas. Remove the test tube from the water and place it mouth down on the lab bench so that the gas does not escape. Repeat step 3 three more times with the other test tubes this time filling ½, 1/3 and 1/12 of the test tube with acetylene, respectively. Lift each tube from the water, always keeping them inverted. Allow air to replace the water that urns out of the test tubes. Place you8r thumb over the end of each test tube and shake each tube for 20 seconds to mix the air and ethyne. Place each test tube mouth down on the lab bench. One at a time, hold each test tube horizontally and bring a burning splint close to its mouth. Wait until each reaction is complete and then place the test tube back down on the lab bench. Observe each test tube carefully and complete the observation table. Observations Table 1: (9 marks, C) Sample Amount of Ethyne / Air Observations Diagram of Observations after Gas Test 1 1/1 2 1/2 3 1/3 4 1/12 Discussion Questions Write the BALANCED, including the states, chemical reaction for the production of ethyne, C2H2 , from CaC2 and water. (2 marks, I) What did you observe as the amount of oxygen in each test tube increased? (1 mark, I)
Day%2014-%20Combustion%20Lab.docx