into a 5 mL conical vial 1mL of mixed 1:1 sulfuric acid and nitric acid was added 0.5 g of finely divided naphthalene was added in small portions to the solution while stirring after each addition and cooling to keep the temperature around 45-50 c the reaction mixture was then stirring in a 60 c water bath for 20 minutes after the addition of naphthalene