A Novel W-Tube for Microscale Experiments in Chemistry By Mr. H. O. Gupta

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.