Final answer:
Fractions containing only butanoic acid are Fraction 2 and Fraction 3. Fraction 1 contains only 2-chloroheptane. Fraction 1 is a mixture of both compounds.
Step-by-step explanation:
The fractions that contain only butanoic acid are Fraction 2 and Fraction 3.
The fraction that contains only 2-chloroheptane is Fraction 1.
The fraction that is a mixture of the two compounds is Fraction 1.