Number of moles of oxygen required for the complete combustion of butane are

Options

A. 6
B. 7.5
C. 6.5
D. 7

Answer

To determine the number of moles of oxygen required for the complete combustion of butane (C₄H₁₀), we can follow these steps:

### Step 1: Write the balanced chemical equation for the combustion of butane.
The complete combustion of butane can be represented by the following equation:

\[ \text{C}_4\text{H}_{10} + \text{O}_2 \rightarrow \text{CO}_2 + \text{H}_2\text{O} \]

### Step 2: Balance the equation.
1. **Count the number of carbon (C) atoms**: Butane has 4 carbon atoms, so we will need 4 CO₂ molecules.
2. **Count the number of hydrogen (H) atoms**: Butane has 10 hydrogen atoms, so we will need 5 H₂O molecules (since each water molecule has 2 hydrogen atoms).

The partially balanced equation now looks like this:

\[ \text{C}_4\text{H}_{10} + \text{O}_2 \rightarrow 4 \text{CO}_2 + 5 \text{H}_2\text{O} \]

3. **Count the total number of oxygen atoms needed**:
- From 4 CO₂, we get \(4 \times 2 = 8\) oxygen atoms.
- From 5 H₂O, we get \(5 \times 1 = 5\) oxygen atoms.
- Total oxygen atoms needed = \(8 + 5 = 13\).

4. **Determine the moles of O₂ required**: Since O₂ has 2 oxygen atoms per molecule, we will need:

\[ \text{Moles of } O_2 = \frac{13}{2} = 6.5 \]

### Step 3: Conclusion
Thus, the number of moles of oxygen required for the complete combustion of one mole of butane is **6.5 moles**.

### Final Answer
The answer is **6.5 moles** of oxygen.

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