The oxygen for combustion is usually taken from air, which is about 20% oxygen. Higher flame temperatures can be attained when fuels are burned with higher concentrations of oxygen. The acetylene torch used for welding and cutting metal uses pure oxygen gas to obtain very high flame temperatures (about 3500 C). Given the list of options, select the correct answer to this question. Write a balanced equation for the combustion of acetylene, CH, What is the coefficient in front of O, in the properly balanced equation? 5 3 2 1