The reaction between silver nitrate and sodium chloride is an example of which type of reaction?

• A. Precipitation reaction
• B. Combustion reaction
• C. Redox reaction
• D. Acid-base reaction

Answer: (A)

When two soluble salts in solution react to form an insoluble solid, that solid is called a precipitate, so the reaction is a precipitation reaction. In this case, silver nitrate and sodium chloride swap partners to give silver chloride, which is only sparingly soluble and comes out as a solid, and sodium nitrate, which stays dissolved. The visible result is the formation of a solid from ions in solution, which is the hallmark of a precipitation reaction.

This isn’t a combustion reaction (no burning or oxygen reacting with a fuel), nor a redox reaction (oxidation states don’t change for the elements involved), nor an acid-base reaction (no transfer of H+ or OH− to form water).