An Improved Victor-Meyer Apparatus The Victar-Meyer method for determining the molecular weight of a volatile The usual liquid is a standard undergraduate physical methods e~periment.'.~ apparatus, however, is tedious to use and does not give reliable and reproducible results. This note describes an improved apparatus that is easy to use and gives reproducible results, limited in accuracy primarily by the precision of the syringe used. The apparatus consists of a250-ml round bottom flask with three ground glass necks. This flask is the volatilizing chamber and sits on a steam bath. One P-. of the necks of the flask is connected t o a stopcock that can he opened for flushing out the system. The middle neck is fitted with a steam condenser, which then leads t o a gas huret. The third neck is fitted with a robber septum. The volatile liquid is introduced into the chamber by injecting it with a hypodermic svrinee .. throueh this seotum. The volume of the liauid samole is measured with theqringe, and the weight of thesampledetermined from its.;olume and density. The limiting suurcr u l error in the experiment I L F I ~this ~ apparatus is the volume of the l q n d snmpk. The (us?of mcdrrn volummriu syringes, huuevw, allows the routine drrrmmination ol mulerular we~ghwtg~uithm1" .much lwtlrr than wuh previously published techniques.
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'Shoemaker, David P., and Garland, Carl W., "Experiments in Physical Chemistry," 2nd ed., McGraw-Hill Book Company, New York, 1962, p. 49. 2Crockford, H. D., and Nowell, J. W., "Laboratory Manual of Physical Chemistry," John Wiley & Sons, NewYork, 1956, p. 39. Roanoke College Salem, Virginia 24153
B. P. Huddle Kenton Whitmire
Volume 54, Ntimber 4, April 1977 1 261
