MOLE TO MOLE RATIO Chapter 9 section 2

Mole to Mole Ratio The coefficient in a balanced chemical equation can be used to determine the relative number of molecules, formula units, or moles of a compound involved in a chemical reaction. The coefficients can also be used to write a Molar Ratio. Molar ratios are conversion factors that can be used to relate: Moles of product formed from a certain number of moles of a reactant. Moles of reactant needed to form a certain number of moles of a product. The number of moles of a particular reactant needed to completely react with a certain number of moles of a second reactant.

For the following reaction 4 NH3 + 5 O2  4 NO + 6 H2O the following molar ratios can be written: 4 mol NH3 4 mol NH3 4 mol NH3 5 mol O2 4 mol NO 6 mol H2O 5 mol O2 5 mol O2 4 mol NO 4 mol NO 6 mol H2O 6 mol H2O

Sample Question What is the molar ratio between Li and N2 (both reactants) in a combination reaction? 6Li + N2  2Li3N 6 mol Li 1 mol N2 1 mol N2 6 mol Li