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

Answer 1

All of your pentanols have molecular mass that is 88. One thing that can help you to determine order of evaporation of pentanols is boiling temperature. Here is the list of pentanols and their boiling temperatures:
1-pentanol / 137-139 °C
2-pentanol / 119.3 °C,
3-pentanol / 115.3 °C
As can you see second product is 2-pentanol.