AgBr (s) + 2 NH4OH (aq) ⇌ [Ag(NH3)2]+ (aq) + Br- (aq) + 2 H2O (l)
Here's the breakdown:
* AgBr (s): Silver bromide is a pale yellow solid, practically insoluble in water.
* NH4OH (aq): Ammonium hydroxide is a weak base, existing in equilibrium with ammonia (NH3) and water.
* [Ag(NH3)2]+ (aq): This is the diamminesilver(I) ion, a colorless complex ion formed by the reaction. It's soluble in water.
* Br- (aq): Bromide ions are released into the solution.
* H2O (l): Water is produced as a byproduct of the reaction.
The key point is that the silver bromide dissolves in the presence of ammonium hydroxide due to the formation of the soluble diamminesilver(I) complex ion. This reaction is an example of a complexation reaction.
Important Note: The reaction is an equilibrium reaction, meaning it can proceed in both directions. The addition of excess ammonium hydroxide will favor the formation of the diamminesilver(I) complex, driving the reaction forward and dissolving more AgBr.
