(A true story.) While organizing the undergraduate stockroom, a new chemistry professor found a half-gallon jug containing...

Question:

(A true story.) While organizing the undergraduate stockroom, a new chemistry professor found a half-gallon jug containing a cloudy liquid (bp 100–105 °C), marked only “STUDENT PREP.” She ran a quick mass spectrum, which is printed below. As soon as she saw the spectrum (without even checking the actual mass numbers), she said, “I know what it is.”

100 57 80 60 136 107 40 93 20 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 m/z abundance