Naphthalene, C₁₀H₉, is a white crystalline solid and an aromatic hydrocarbon consisting of two joined benzene rings. It is more reactive than benzene. Naphthalene is produced from coal tar and is used to make phthalic anhydride (see acid anhydride), as an intermediate in dye manufacture, and for mothballs. Molecular weight 128.2, melting point 81°C, boiling point 218°C.