Question

1. when silver nitrate and sodium iodide were mixed, a white precipitate formed. its identity is either silver iodide or sodium nitrate. use the results from your experiment to help you decide which of these two substances formed the precipitate.

Explanation:

Step1: Recall solubility rules

According to solubility rules, most nitrate - salts are soluble in water. Sodium nitrate ($NaNO_3$) is a nitrate - salt and is highly soluble in water.

Step2: Consider silver - iodide solubility

Silver iodide ($AgI$) is insoluble in water. When silver nitrate ($AgNO_3$) and sodium iodide ($NaI$) react, the chemical reaction is $AgNO_3+NaI = AgI\downarrow+NaNO_3$. The formation of a precipitate indicates an insoluble product. Since sodium nitrate is soluble and silver iodide is insoluble, the precipitate must be silver iodide.

Answer:

The precipitate is silver iodide.