Describe the preparation of benzenediazonium chloride and explain why diazonium salts are not generally stored.

Benzenediazonium chloride is prepared by diazotization, involving the reaction of aniline with sodium nitrite (NaNO₂) and hydrochloric acid (HCl). The reaction forms benzenediazonium chloride, which can be isolated as a white crystalline solid. Diazonium salts are not generally stored due to their instability. They are prone to decomposition, leading to the release of nitrogen gas, which poses explosion hazards. The decomposition can be initiated by heat, light, or impurities. Therefore, diazonium salts are typically prepared and used immediately in various synthetic reactions without long-term storage.