Stoichiometry Problem

Question

4. How many moles of hydrogen molecules could be produced by the reaction of 50 moles of sodium atoms with water?

                                                    Na   +      H2O         NaOH      +      H2     

Answer 1

First balance the reaction to get correct mole ratios: 2 Na + 2 H₂O --> 2 NaOH + H₂.

Now we see that the mole ratio of H₂ to Na is 1:2, therefore 50/2 = 25 moles of H₂ are produced.