Question #73ac3

1 Answer
Jan 6, 2015

You are indeed dealing with a double replacement precipitation reaction, a reaction in which two soluble ionic compounds react to form an insoluble precipitate.

If you are familiar with the solubility rules (more here: http://www.csudh.edu/oliver/chemdata/solrules.htm), you'll recognize that both NaOH (being a hydroxide salt of a group I element) and AgNO3 (a common soluble salt of silver) are soluble in water. The general reaction looks like this

NaOH(aq)+AgNO3(aq)AgOH(s)+NaNO3(aq)

However, this reaction will not create siginificant amounts of AgOH because of the more favorable energetics of this reaction:

2AgOHAg2O(s)+H2O(l)

Silver oxide looks like this:

http://www.sciencephoto.com/media/4351/enlarge

So, your general reaction actually looks like this:

2AgNO3(aq)+2NaOH(aq)Ag2O(s)+2NaNO3(aq)+H2O(l)

Since we are dealing with ionic compounds, the complete ionic equation looks like this:

2Na+(aq)+2OH(aq)+2Ag+(aq)+2NO3(aq)Ag2O(s)+2NO3(aq)+2Na+(aq)+H2O(l)

The net ionic equation, which results from eliminating spectator ions, is:

2Ag+(aq)+2OH(aq)Ag2O(s)+H2O(l)

Here's a video of the reaction: