Question

How can we predict whether a precipitate will be formed or not on mixing two solutions?

Answer 1

A precipitate obtained in a reaction is a solid formed in a double displacement reaction between two aqueous solutions.

For example, when two aqueous solutions (which are clear) reacts forming one aqueous compound and one solid, which is a precipitate.

The solid phase that formed is insoluble in water.

Silver nitrate reacts with sodium chloride, yielding silver chloride and sodium nitrate.

$AgNO_{3}(aq)+NaCl(aq)\rightarrow AgCl(s)+NaNO_{3}(aq)$

The precipitate is AgCl, because it's insoluble.