Final answer:
The empirical formula of the precipitate formed when sodium bromide reacts with silver nitrate is AgBr, as a result of a double-replacement precipitation reaction.
Step-by-step explanation:
The empirical formula of the precipitate formed when sodium bromide reacts with silver nitrate is AgBr. This reaction is a classic example of a precipitation reaction, which occurs when two soluble salts react in solution to form an insoluble solid called a precipitate. The precipitation process can be understood by analyzing the solubility rules and the solubility product constant (Ksp) for the compounds involved.
When a solution containing sodium bromide (NaBr) is mixed with a solution of silver nitrate (AgNO3), a double-replacement reaction occurs, resulting in the formation of sodium nitrate (NaNO3), which stays dissolved, and silver bromide (AgBr), which precipitates out of the solution:
AgNO3 (aq) + NaBr (aq) → AgBr (s) + NaNO3 (aq)
The solubility of AgBr is lower than AgCl, which means AgBr will precipitate first if both bromide (Br−) and chloride (Cl−) ions are present in the solution.