Illustrated Guide to Home Chemistry Experiments

266 DIY Science: Illustrated Guide to Home Chemistry Experiments

RQEWEvI UESTIOnS

q 1 : The actual molar mass of acetone is 58.09 g/mol. How closely did your experimental result correspond to the actual value?
Propose at least two possible explanations for any variation in your result.

q: 2 Could this method be used unmodified to determine the molar mass of trichloroacetic acid? If not, why not, and what
modification to the apparatus would be required to determine the molar mass of trichloroacetic acid?

dISoALp S :

No waste is produced in

this lab session.

TABLE 14-5: Determine molar mass from vapor density—observed and calculated data

Item value

A. Mass of flask + aluminum foil _______._____ g

B. Temperature of water bath _______._____ K

C. Mass of flask + aluminum foil + condensed acetone _______._____ g

D. Mass of condensed acetone (C – A) _______._____ g

E. Moles of condensed acetone (D/58.09 g/mol) ___.________ mol

F. Volume of flask _______._____ mL

G. Atmospheric pressure ______._____ kPa

H. Molar mass of acetone _______._____ g/mol