What is the percentage yield of the major product?

• A. 64.43%
• B. 99.44%
• C. 99.93%
• D. 76.25%

Answer: (B)

Verified step by step guidance

1. Identify the starting material as isobutane, which is a branched alkane with the formula C4H10.
2. Recognize that the reaction involves bromination using Br2 in the presence of heat, which suggests a radical halogenation mechanism.
3. Understand that in radical bromination, the major product is typically formed by the substitution of a hydrogen atom at the most stable radical position, which is the tertiary carbon in isobutane.
4. Determine that the major product will be 2-bromo-2-methylpropane, as the bromine will preferentially substitute at the tertiary carbon due to the stability of the tertiary radical.
5. Calculate the percentage yield of the major product by comparing the amount of the major product formed to the theoretical maximum amount possible, using the given options to identify the correct yield.