Flask Support for Weighings Round-bottom flasks are commonly supported for weighings by placing them in a beaker, a Neoprene@rubber cone, or a cork (or Suberite) ring. We used an electronic digital balance with a limited capacity of 200 g, which left little leeway for weighing reagents into larger (e.g., 500-ml) flasks. A cork ring -11 cm a d . weighed about 40 gas did a Neoprene cone (Arthur H. Thomas #6). A smaller Neopreneacone (#5 size) still weighed over 20 g and offered less stable support. By threading a length of heavy copper wire through a 15-cm length of plain rubber tubing, we could form the tubing into a circle which adequately supported round bottom flasks for weighing. These tubing circles typically weigh less than 10 g and cost very little. Several can be prepared to accommodate variously sized flasks. Robert Rothchlld The City University of New York. John Jay College of Criminal Justice 445 West 59th Street. New York. NY 10019
Volume 59
Number 4
A ~ r i l1982
339
