NaNO₂
The following solutions are prepared in advance:
Phenol: 15.06 g (160 mmol) dissolved in 400 mL ethanol 96 %
1-naphthol: 17.3 g (120 mmol) dissolved in 400 mL ethanol 96 %
2-naphthol: 11.54 g (80 mmol) dissolved in 400 mL ethanol 96 %
The solutions should be colorless; if needed a "spatula-tip" full of activated charcoal powder is added. After shaking, the suspension is filtered.
Reagent solution (Diazo component): 40 mL of 0.5 % aqueous NaNO₂ solution + 40 mL of 0.5 % solution of sulfanilic acid in 2 N acetic acid

Glass wares:
3 conical measures,graduated, 500 mL

3 glass stirring rods

5 beakers 50 mL

3 beakers 500 mL

graduated cylinder 200 mL

:Experimental procedure
Each of three conical measures is filled with alcoholic solutions of phenol, 2-naphthol and 1-naphthol, respectively. Afterwards the diazo component is added while stirring.