Four pure liquids have the following normal boiling points: methanol 65 °C, butanone 80 °C, octane 126 °C, propanoic acid 141 °C. A fractional distillation is performed at 1atm on an equimolar mixture of all four liquids. Which component is expected to appear as the second major fraction collected (after the first fraction has largely ceased)?
a) Propanoic acid (141 ∘C)
b) Methanol (65 ∘C)
c) Butanone (80 ∘C)
d) Octane (126 ∘C)