Question

What is the isomer of C5H12 that will give only a single monochlorination product?

1) 2-methylbutane
2) 2,2-dimethylpropane
3) n-pentane
4) 2,3-dimethylbutane

Answer 1

The only isomer of C5H12 that will give a single monochlorination product is 2,2-dimethylpropane, due to its high symmetry and equivalent hydrogen positions.

Step-by-step explanation:

The student's question asks to identify the isomer of C5H12 that will give only a single monochlorination product. The isomer that fulfills this criterion is 2,2-dimethylpropane. This is because 2,2-dimethylpropane has all hydrogen atoms in equivalent positions due to its high symmetry. In contrast, the other isomers listed have hydrogen atoms in different chemical environments, which would lead to multiple monochlorination products through substitution.

To visualize, 2,2-dimethylpropane is a highly branched molecule where all the hydrogens are equivalent to one another. When a chlorine atom replaces any of these hydrogens, it will always create the same product, unlike structures with different types of hydrogen atoms, such as in n-pentane or the other isomers listed.

Therefore, the correct answer is option 2: 2,2-dimethylpropane.