) Next, describe what happened when silver nitrate was added to the control tube? How does equilibrium shift and what observations demonstrate this?
When silver nitrate was added to the control tube, the following reaction occurred:
NaCl (aq) + AgNO3 (aq) -> NaNO3 (aq) + AgCl (s)
In this reaction, silver nitrate reacts with sodium chloride to form sodium nitrate and a white precipitate of silver chloride. This reaction demonstrates a shift in equilibrium towards the formation of the precipitate, as the addition of silver nitrate drives the reaction forward by removing chloride ions from the solution and forming insoluble silver chloride.
The observation of a white precipitate forming in the control tube is evidence of this shift in equilibrium. The formation of the solid silver chloride indicates that the equilibrium has shifted towards the side of the equation where the precipitate is formed. This demonstrates that the addition of silver nitrate has driven the equilibrium towards the formation of the precipitate, as predicted by Le Chatelier's principle.