Answer:
We need 50.6 grams of oxygen
Explanation:
Step 1: Data given
Mass of ethane = 13.6 grams
Molar mass of ethane = 30.07 g/mol
Step 2: The balanced equation
2C2H6 + 7O2 → 4CO2 + 6H2O
Step 3: Calculate moles ethane
Moles ethane = mass ethane / molar mass ethane
Moles ethane = 13.6 grams / 30.07 g/mol
Moles ethane = 0.452 moles
Step 4: Calculate moles oxygen
For 2 moles ethane we need 7 moles O2 to produce 4 moles CO2 and 6 moles H2O
For 0.452 moles ethane we need 3.5*0.452 = 1.582 moles O2
Step 5: Calculate mass O2
Mass O2 = moles O2 * molar mass O2
Mass O2 = 1.582 moles * 32.0 g/mol
Mass O2 = 50.6 grams
We need 50.6 grams of oxygen