Hydrogen-filled balloon was ignited and 1.50 g of hydrogen reacted with 12.0 g of oxygen. how many grams of water vapor formed? (assume that water vapor is the only product.)

             13.39 g of H₂O

Solution:

The Balance Chemical Reaction is as follow,

                                          2 H₂  +   O₂    →    2  H₂O

Step 1: Find out the limiting reagent as;

According to Equation ,

            4.032 g (2 mole) H₂ reacts with  =  32 g (1 moles) of O₂

So,

                  1.5 g of H₂ will react with  =  X g of O₂

Solving for X,

                      X  =  (1.5 g × 32 g) ÷ 4.032 g

                      X  =  11.90 g of O₂

It means for total oxidation of Hydrogen we require 11.90 g of O₂, but we are provided with 12 g of O₂. Therefore, H₂ is the limiting reagent and will control the yield.

Step 2: Calculate Amount of H₂O produced as;

According to Equation ,

              4.032 g (2 mole) H₂ produces  =  36 g (2 moles) of H₂O

So,

                       1.50 g of H₂ will produce  =  X g of H₂O

Solving for X,

                      X =  (1.50 g × 36 g) ÷ 4.032 g

                      X  =  13.39 g of H₂O

And this answer is correct.