2.911 grams of ethanol C2H5OH is burned and produces how many grams of water vapor? Please help me or I'm dead.

3.4g

Explanation:

Given parameters:

Mass of ethanol  = 2.911g

Unknown:

Mass of water vapor = ?

Solution:

To solve this problem, let us write the balanced reaction equation first;

             C₂H₅OH  + 3O₂  → 2CO₂  + 3H₂O

Now find the number of moles of ethanol;

  Number of moles  =

    Molar mass of ethanol = 2(12) + 5(1) + 16 + 1 = 46g/mol

  Number of moles  =   = 0.06mole

  So;

       1 mole of ethanol will produce 3 moles of water vapor

      0.06mole of ethanol will produce 0.06 x 3  = 0.19moles of water vapor

 Mass of water vapor  = number of moles x molar mass

   Molar mass of H₂O  = 2(1) + 16  = 18g/mol

  Mass of water vapor  = 0.19 x 18  = 3.4g