Final answer:
To completely burn 1 molecule of C₇H₁₆, 11 molecules of O₂ are required as per the balanced chemical reaction: C₇H₁₆ + 11O₂ → 7CO₂ + 8H₂O.
Step-by-step explanation:
To determine how many molecules of O₂ are required to completely burn 1 molecule of C₇H₁₆, we need to balance the chemical reaction. The complete combustion reaction is as follows:
C₇H₁₆ + O₂ → 7CO₂ + 8H₂O
To balance the reaction, we start by balancing the carbon and hydrogen atoms:
- Since there are 7 carbon atoms in n-heptane (C₇H₁₆), we need 7 molecules of CO₂, each containing 1 carbon atom, to balance the carbon atoms.
- Since there are 16 hydrogen atoms in n-heptane, we need 8 molecules of H₂O, each containing 2 hydrogen atoms, to balance the hydrogen atoms.
Now, the carbon and hydrogen atoms are balanced, but we need to balance the oxygen atoms:
- On the product side, there are 7 × 2 = 14 oxygen atoms from CO₂ and 8 × 1 = 8 oxygen atoms from H₂O, adding up to 22 oxygen atoms in total.
- Since O₂ is a diatomic molecule, we divide the total number of oxygen atoms needed by 2 to find the required number of O₂ molecules.
- 22 oxygen atoms / 2 = 11 molecules of O₂.
Therefore, the balanced chemical equation is:
C₇H₁₆ + 11O₂ → 7CO₂ + 8H₂O
Thus, 11 molecules of O₂ are required to completely combust 1 molecule of C₇H₁₆.