According to the chemical equation

2C2H6(g) + 7O2(g) ---> 4CO2(s) + 6H2O(g)

c) how many mol of ethane, assuming excess dioxygen, are required to form 3.7 mol of water?


The approach is nearly identical to that used in part a). We must use the stoichiometric ratio between water and ethane to answer the question. This ratio is obtained from the balanced chemical equation. According to the balanced chemical equation six mol of water are formed when two mol of ethane, C2H6, react. Water and ethane always combine in this ratio according to this equation. We can use this relationship as a unit conversion factor to convert between mol of water and mol of ethane.