What Is the Reaction for NaOH and AgNO3?

The reaction between NaOH and AgNO3 produces NaNO3, Ag2O and H2O. The common names of the chemicals in the reaction are sodium hydroxide, silver nitrate, sodium nitrate, silver oxide and water. The silver oxide precipitates out of solution as a brown solid, while the sodium nitrate remains in aqueous solution.

This reaction is used to create Tollens’ reagent, a compound used to differentiate between aldehydes and ketones. After the silver hydroxide precipitates out of solution, aqueous ammonia is added until the silver hydroxide dissolves. This reaction produces Tollens’ reagent and sodium hydroxide, and it is also used in the production of silver mirrors.

It is also possible for this reaction to produce two molecules of AgOH, or silver hydroxide, instead of one molecule of silver oxide and one molecule of water. Producing silver oxide and water is the more energetically favorable outcome, so only trace amounts of silver hydroxide are formed.

Silver oxide is photosensitive, and preparations using this reaction have a shelf life of less than 24 hours. If ammonia is added to create Tollens’ reagent, there is an additional risk: the compound can form silver nitride. Silver nitride is highly explosive. This risk is mitigated by acidifying the mixture when work is complete.