Table 1 shows the octane number of some hydrocarbons. Hexane has the lowest octane number of the four compounds listed. Explain why hexane has the lowest octane number.   Table 1 Name Octane number Hexane

1. Table 1 shows the octane number of some hydrocarbons. Hexane has the lowest octane number of the four compounds listed. Explain why hexane has the lowest octane number.

Table 1

2. A molecule of the hydrocarbon C₁₂H₂₆ was cracked to give 2 molecules of ethene, C₂H₄, one of propene, C₃H₆ and one other molecule. Write the molecular formula for the one other molecule.