Fuels (antiknock rating): The octane number scale assigns a value of zero to which reference fuel? Recall the two primary standards used to define octane numbers. Choose the correct option.

Q: Fuels (antiknock rating): The octane number scale assigns a value of zero to which reference fuel? Recall the two primary standards used to define octane numbers. Choose the correct option.

Concept/Approach Octane number is defined by comparison with a mixture of iso-octane (100) and n-heptane (0). Thus, the zero point corresponds to n-Heptane.

Difficulty: Easy

2-Methyl octane
n-Heptane
Iso-octane (2,2,4-trimethylpentane)
3-Methyl octane

Correct Answer: n-Heptane

Explanation:

Concept/Approach
Octane number is defined by comparison with a mixture of iso-octane (100) and n-heptane (0). Thus, the zero point corresponds to n-Heptane.

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