Answer:
22.715 moles of oxygen are used
Explanation:
Given data:
Number of moles of ethane = 6.49 mol
Number of moles of Oâ‚‚ required = ?
Solution:
Chemical equation:
2C₂H₆ + 7O₂    →   4CO₂ + 6H₂O
Now we will compare the moles of oxygen with ethane.
          Câ‚‚H₆      :      Oâ‚‚ Â
            2        :       7
           6.49      :      7/2×6.49 = 22.715 mol
Thus, 22.715 moles of oxygen are used.