22 November 2002

In lab today, the students determined the value of "R", the ideal gas constant. It was a fun experiment in which they reacted magnesium metal with concentrated hydrochloric acid, collecting the hydrogen gas in a long graduated glass tube called a eudiometer. From the amount of magnesium they started with, and the amount of gas collected, and accounting for the air pressure, temperature, and vapor pressure of water, they could calculate the constant. I think most of them got pretty good data. One group, however, used too much magnesium, thus producing more than the eudiometer could hold. They had to start over.

DWL