Q.Explain what happens to a solution of benzenediazonium chloride if it is allowed to warm above $10^\circ\text{C}$, and name the organic product formed together with the gas that is evolved.

On warming, water attacks the diazonium carbon as the departing nitrogen molecule leaves: $\text{C}_6\text{H}_5\text{N}_2^+ + \text{H}_2\text{O} \xrightarrow{\Delta} \text{C}_6\text{H}_5\text{OH} + \text{N}_2\uparrow + \text{H}^+$. This spontaneous hydrolysis is exactly why diazonium salts must be kept cold and used immediately for whatever OTHER transformation is actually …

Identify water itself as the available nucleophile once the salt is no longer held col …

Assuming the diazonium salt is simply stable indefinitely once formed -- its reactivity toward warming/water is an intr …