Answer:
40 % A, 26 % B, and 34 % C
Explanation:
2,4-Dimethylpentane (1) has three sets of equivalent H atoms:
- Four CH₃ groups (12 H, 1°)
- One CH₂ group (2 H, 2°)
- Two CH groups (2 H, 3°)
Thus, replacement of an H atom can give three products:
- 1-Chloro-2,4-dimethylpentane (A)
- 3-Chloro-2,4-dimethylpentane (B)
- 2-Chloro-2,4-dimethylpentane (C)
The relative reactivities of the three types of hydrogen atoms to substitution by Cl are
1°:2°:3° = 1:3.9:5.2
We can predict the distribution of monochloro products by combining statistics with the reactivity factors.
[tex]\begin{array}{cccrccr} & & \textbf{Rel.} & \textbf{Rel.}\; & \textbf{Fraction} & \mathbf{\%}&\\\textbf{Type} & \textbf{No.} & \textbf{Rate} & \textbf{Amt.} & \textbf{Yield} & \textbf{Yield}& \\1^{\circ} & 12 & 1 & 12.0 & \dfrac{12.0}{30.2} & 40 \\\\2^{\circ} & 2 &3.9 & 7.8 & \dfrac{7.8}{30.2} & 26 &\\\\3^{\circ} & 2 & 5.2 & 10.4 &\dfrac{10.4 }{30.2}&34 &\\&& \textbf{Tot.} & \mathbf{30.2} && \mathbf{100} &\\\end{array}\\[/tex]
The product mixture contains 40 % A, 26% B, and 34 %C.
