Featured in PASCO’s College Chemistry Instructor Guide

College Chemistry Instructor Guide

(PS-3803A)

College Instructor edition with 36 experiments covering introductory and general chemistry topics.

Molar Mass of Liquid

Lab Summary

Use a stainless steel temperature sensor to determine the molar mass of an unknown volatile liquid at the boiling temperature of water and atmospheric pressure.

Theory

Students determine the molar mass of an unknown volatile liquid at the boiling temperature of water and at atmospheric pressure.

Method

Students gain experience conducting the following procedures:

  • Using hot and cold water baths to evaporate and condense an unknown volatile liquid, measuring the mass of a flask with and without the condensed unknown liquid.
  • Obtaining the mass, pressure, temperature, and volume of the evaporated volatile liquid.
  • Using the Ideal Gas Law to calculate the molar mass of the volatile liquid.

Sensors / Equipment Used:

PASPORT Chemistry Sensor

(PS-2170)

Allows students to measure Temperature, pH/ISE/ORP, Absolute Pressure & Voltage in one sensor. For use with PASPORT Interfaces.

Materials Used:

Beaker, 400-mL - 2
Erlenmeyer flask, 125-mL 
Graduated cylinder, 100-mL 
Hot plate with magnetic stirrer and stir bar 
Balance - 1 per class
Ring stand 
Clamp - 2
Unknown volatile liquid (use acetone) - 8 mL
Aluminum foil, about 4-cm by 4-cm 
Paper towel, sheets - 2 or 3
Dropper 
Water - 600 mL

The Associated Bundle:

Advanced Chemistry Standard Sensor Bundle

(PS-2928A)

Contains the probeware for completing experiments in the College Chemistry lab manual.

Interface Required

This experiment may require software and an interface for data collection.