Equilibrium and Le'Chatlier's Principle
You would see a picture like this
and you might write something like the following in your notebook or on your data sheet:
System: AgCl system
Stress Applied: added AgNO3
Observations: The addition of AgNO3 solution caused the formation of a white precipitate indistinguishable from the AgCl already in the tube.
Chemical Explanation: The addition of AgNO3 increased the concentration of silver ions in solution. This increased the rate of the forward reaction. As a result the equilibrium shifted to the right. In doing so more AgCl precipitate is formed.