Consider the (unbalanced) reaction for the combustion of acetylene: C2H2(g) + O2(g) CO2(g) + H2O(g) a) The stoichiometric coefficients in the balanced reaction for C2H2, O2, CO2, and H2O are, respectively: 2.5, 1, 1, 2 1, 2.5, 2.5, 1 1, 2.5, 2, 1 1, 1, 2, 1 b) 67.5 grams of acetylene are mixed with an excess of oxygen. How many moles of acetylene is this?