the use of boiling chips is that it traps air bubbles and it provides spaces for the solvent vapor can form. When the boiling process is started heated chips will release small bubbles to promote...
http://orgchem.colorado.edu/hndbksupport/dist/boilchip.html
Boiling chips are small, insoluble, porous stones made of calcium carbonate or silicon carbide. These stones have pores inside which...
Boiling chips are used to ensure that a liquid being heated does not super-heat and 'erupt' or explode but rather has a 'seed' surface to initiate smooth boiling.