Gasoline Is Primarily a Mixture of Hydrocarbons and Is Sold

question 26

Multiple Choice

Gasoline is primarily a mixture of hydrocarbons and is sold with an octane rating that is based on a comparison with the combustion properties of isooctane. Gasoline usually contains an isomer of isooctane called tetramethylbutane (C₈H₁₈) , which has an enthalpy of vaporization of 43.3 kJ/mol and a boiling point of 106.5°C. Determine the vapor pressure of tetramethylbutane on a very hot summer day when the temperature is 38°C.

• A) 80.0 torr
• B) 36.7 torr
• C) 67.8 torr
• D) 47.9 torr
• E) 89.3 torr

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Definitions:

Physician

A medical professional who diagnoses and treats illnesses and injuries.

Placebo

A substance or treatment with no therapeutic effect, often used as a control in testing new drugs.

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A detrimental health effect resulting from the negative expectations of the patient towards a treatment or medication.

Dependent Variable

In an experiment or clinical trial, the variable that represents the effect or outcome of interest.