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Online Chemistry Labs | Learning Objectives

Background:

This laboratory introduces students to a method of identifying a metal by the amount of H2 released when a known mass reacts with excess HCl in a constant volume pressure vessel. The ideal gas law if used to determine moles of H2 gas produced at a measured temperature, after correcting for the vapor pressure of water. A calibration run with a massed Zn sample is used to determine the vessle volume.  Student are assigned two radnomly selected unknown metals to identify. The experiment also asks students to evaluate error sources such as temperature drift a pressure leak.

 Metals + HCl

Learning Objectives:

  1. Become familiar with the principles of a pressure vessel designed to be evacuated and monitor pressure rise with a temperature drift.
  2. Use the ideal gas law, corrected for the vapor pressure of water. 
  3. Perform the calculation of the volume of the pressure vessel.
  4. Illustrate how to determine the moles of hydrogen gas produced by a measured mass of unknown.
  5. Be able to deal with temperature drift and pressure corrections.
  6. Suggest new experiments to detect leaks in the apparatus.