Question

Wine goes bad soon after opening because the ethanol ch3ch2oh in it reacts with oxygen gas o2 from the air to form water h2o and acetic acid ch3cooh , the main ingredient of vinegar. what mass of ethanol is consumed by the reaction of 3.84g of oxygen gas? be sure your answer has the correct number of significant digits.

Answer 1

The balanced chemical equation of the reaction described above is,

                            C2H6O + O2 --> H2O  + C2H4O2

If we have 3.84 g of oxygen, we divide by its molar mass.
 
                               n = (3.54 g Oxygen gas) x (1 mole O2/ 32 g O2)
                                 n = 0.11 moles O2

Using ratio and proportion,

               number of moles of ethanol = (0.11 moles O2) x (1 mole C2H6)
                                                  = 0.11 moles C2H6

Then, we multiply the calculated value to its molar mass, 46 grams /mol.
                    mass of ethanol = (0.11 mol) x (46 grams / mol)
                                                = 5.06 grams