Question

Gasoline is a mixture composed primarily of hydrocarbons such as isooctane, which is also known as 2,2,4-trimethylpentane.

Gasoline is assigned a number called an octane rating. Gasoline with an octane rating of 87 performs the same as a mixture that consists of 87% isooctane and 13% heptane.
An alternative fuel, E-85, can be used in some automobiles. This fuel is a mixture of 85% ethanol and 15% gasoline.

State the octane rating of a gasoline sample that performs the same as a mixture consisting of 92% isooctane and 8% heptane.
Identify the functional group in a molecule of ethanol in the alternative fuel E-85.

Answer 1

Because of the 92% isooctane, the gasoline sample's octane rating is 92. The functional group in ethanol is the hydroxyl group.