Lab Question

Suppose you performed a distillation of a solution containing 1-pentanol (C5H12O), 2-pentanol (C5H12O), 3-pentanol (C5H12O), and methyl alcohol (CH4O). All three pentanols here have the same chemical formula, but they do have a different arrangement of their atoms (i.e. they are shaped differently), so this makes them have slightly different properties from one another. During the distillation, you collect the FIRST product that comes out, and set it aside. Then, you collect the SECOND product that comes out, and set it aside Then, you collect the THIRD product, analyze it, and determine that it has a formula mass of approximately 88 amu. What is the identity of this second product that you collected? How do you know (discuss ALL relevant data)?