Mole Ratios in Chemical Equations

LG: I can predict the amount (moles) of reactant or product used or created during a chemical

reaction

Mole Ratios• Balanced chemical equations indicate the

ratio of one chemical to another used in a reaction

• This ratio indicates the relative number of entities, not the mass, of each substance

• Example:2 H2(g) + O2(g) 2 H2O(g)

Gimme S’more Stoichiometry!

• Use the recipe for S’mores to investigate the ratios of reactants and products in chemical reactions

Example• The Haber process is used to manufacture

ammonia, used in fertilizer, from hydrogen and nitrogen gas

N2(g) + H2(g) NH3

• Balance the equation above to determine the mole ratio in the reaction– How many moles of hydrogen would be required to react with

6.2 mol of nitrogen gas?– If the amount of nitrogen was unlimited, how many moles of

ammonia could be produced from 10.8 mol of hydrogen?– If you had 3.0mol of N2 and 8.0mol of H2, which substance would

run out first (limiting reagent)? How much product could be made? How much excess reagent would remain after the reaction?

Homework

• Complete Mole Ratios Handout