Propane reacts with chlorine in sunlight to give two products. 1-chloropropane is obtained in 44% yield and 2-chloropropane is obtained in 56% yield of the total product. What will be the percent yield of the major product obtained when butane is treated with `Cl_(2)` in similar conditions

Explanation

To solve the problem, we need to analyze the chlorination of butane in the presence of chlorine and sunlight, similar to the reaction of propane with chlorine. Here are the steps to find the percent yield of the major product when butane is treated with chlorine.

### Step-by-Step Solution:

1. **Identify the Structure of Butane**:
- Butane has the molecular formula C₄H₁₀ and can be represented as CH₃-CH₂-CH₂-CH₃.

2. **Identify the Types of Hydrogens**:
- In butane, we have:
- 3 primary (1°) hydrogens from the terminal CH₃ groups.
- 2 secondary (2°) hydrogens from the CH₂ groups.
- The reactivity of these hydrogens is different, with primary hydrogens being less reactive than secondary hydrogens.

3. **Determine the Reactivity Ratio**:
- The reactivity ratio for hydrogen types during chlorination is approximately:
- Primary (1°): 1
- Secondary (2°): 3.8
- Thus, the reactivity for butane can be calculated as follows:
- For primary hydrogens: 3 (number of primary hydrogens) × 1 (reactivity) = 3
- For secondary hydrogens: 2 (number of secondary hydrogens) × 3.8 (reactivity) = 7.6

4. **Calculate the Total Reactivity**:
- Total reactivity = Reactivity from primary + Reactivity from secondary
- Total reactivity = 3 + 7.6 = 10.6

5. **Calculate the Relative Amounts of Products**:
- Let’s denote the products formed:
- Product A (1-chlorobutane) from primary hydrogens = 3
- Product B (2-chlorobutane) from secondary hydrogens = 7.6

6. **Calculate the Percent Yield of Each Product**:
- Percent yield of Product A (1-chlorobutane):
\[ \text{Percent Yield of A} = \left(\frac{3}{10.6}\right) \times 100 \approx 28.3\% \]
- Percent yield of Product B (2-chlorobutane):
\[ \text{Percent Yield of B} = \left(\frac{7.6}{10.6}\right) \times 100 \approx 71.7\% \]

7. **Identify the Major Product**:
- The major product is the one with the higher percent yield, which in this case is 2-chlorobutane (Product B) with a yield of approximately 71.7%.

### Final Answer:
The percent yield of the major product (2-chlorobutane) obtained when butane is treated with Cl₂ in similar conditions is approximately **71.7%**.