The petrol having octane number 80 has ____________?
Correct answer: A. 20% n- heptane + 80% iso-octane
- A. 20% n- heptane + 80% iso-octane
- B. 80% n- heptane + 20% iso-octane
- C. 20% n- heptane + 80% n-octane
- D. 80% n-heptane + 20% n- octane
Explanation
An octane number of 80 means the petrol has the same knocking tendency as a mixture containing 80% iso-octane and 20% n-heptane by volume. Iso-octane defines the 100 reference and n-heptane defines the 0 reference. The usual trap is reversing the percentages, which would represent an octane number of about 20.
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About Alkanes
Alkanes are saturated hydrocarbons containing only carbon-carbon and carbon-hydrogen single bonds, with the general formula CnH2n+2 for open chains. Their structure, isomerism, IUPAC nomenclature, physical properties, combustion, free-radical halogenation and conformations are covered, including the difference between substitution in alkanes and addition in unsaturated hydrocarbons.
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