Explanation:
a) Balanced chemical equation:
C₃H₈ + 5O₂    →     3CO₂ + 4H₂O
b) Mass of oxygen gas needed = ?
Mass of propane = 25 g
Solution:
Number of moles of propane = mass/molar mass
Number of moles = 25 g/ Â 44.1 g/mol
Number of moles = 0.57 mol
now we will compare the moles of oxygen and propane:
              C₃H₈     :      Oâ‚‚    Â
                1      :       5
               0.57     :     5/1×0.57 =  2.85 mol
Mass of oxygen:
Mass = number of moles × molar mass
Mass = 2.85 mol × 32 g/mol
Mass = 91.2 g  Â
c) water vapors produced = ?
Mass of propane = 25 g
Solution:
Number of moles of propane = mass/molar mass
Number of moles = 25 g/ Â 44.1 g/mol
Number of moles = 0.57 mol
now we will compare the moles of water and propane:
              C₃H₈     :      Hâ‚‚O    Â
                1      :       4
               0.57     :     4/1×0.57 =  2.28 mol
Mass of water vapors:
Mass = moles × molar mass
Mass = 2.28 mol × 18 g/mol
Mass = 41.0 g
d)
mass of water vapors produced = 1.5 kg (1500 g)
Mass of propane reacted = ?
Solution:
Number of moles of water vapors:
Number of moles = mass/molar mass
Number of moles = 1500 g/ 18 g/mol
Number of moles = 83.33 mol
now we will compare the moles of water and propane.
    Â
              Hâ‚‚O      :       C₃H₈  Â
                4       :        1
               83.3     :     1/4×83.3 =  20.8 mol
Mass of propane:
Mass = number of moles ×molar mass
Mass = 20.8 mol × 44.1 g/mol
Mass = 917 g