What simple technique can be employed to differentiate the composition of an unidentified mothball (camphor vs naphthalene vs paradichlorobenzene)?
Each substance has a distinct specific gravity, allowing mothballs to be differentiated based on buoyancy (camphor=0.992, naphthalene=1.15, paradichlorobenzene=1.30). Camphor-containing mothballs will float in water while both naphthalene and paradichlorobenzene sink. The latter can be further differentiated using 50% Dextrose solution. Naphthalene will float while paradichlorobenzene sinks. Identification of the type of mothball can be helpful in anticipatory guidance in mothball ingestions.
Michael J. Moss, Kevin F. Maskell, Michelle A. Hieger, Brandon K. Wills & Kirk L. Cumpston (2017) An algorithm for identifying mothball composition, Clinical Toxicology, 55:8, 919 921, DOI: 10.1080/15563650.2017.1319954