A Novel W-Tube for Microscale Experiments in Chemistry By Mr. H.
The generation, collection, and testing of gases in teaching
laboratories usually involves the assembly of a glass apparatus, the
consumption of more reagents than are strictly necessary, the generation of
excess gas, and the disposal of products and unconsumed reagents. We have
devised a simple W-shaped apparatus (Figure 1) by bending glass tubing to
contain all of the chemicals involved and to limit the quantities to
microscale. This tube has two outer sides that are about 4- m long and the
middle sides of about 2-cm long. In one of the outer sides of W-tube a few
milligrams of solid or a few drops of liquid under test is transferred with
the help of a microspatula or a dropper. In the other outer side one or two
drops of liquid reagent that tests the presence or absence of the evolved
gas is transferred. The reagent that would react with the test sample is
then transferred as one or two drops with the help of another dropper into
the first side. The stem of the dropper would make this side airtight. The
generated gas would bubble through the liquid reagent in the other side
showing the chemical change.
Results and Discussion:
The W-tubes were made and tested by the teachers and
students from a few schools for three tests.