What would happen to the color of a dilute solution containing FeCL4 if you added concentrated HCl?
What is FeCl4?
When a dilute solution containing FeCl4 (ferric chloride) is mixed with concentrated HCl (hydrochloric acid), it undergoes a chemical reaction that results in the formation of a new compound. This reaction involves the exchange of ions between the two substances.
FeCl4- + H+ → FeCl3 + HCl
In this reaction, the FeCl4- ion combines with the H+ ion from HCl to form FeCl3 (ferric chloride) and free HCl. The concentration of FeCl3 increases while the concentration of the FeCl4- ion decreases.
Now, if we consider the color of these compounds, FeCl4- is typically a yellow solution, while FeCl3 is a brownish-red solution. So, when concentrated HCl is added to a dilute solution containing FeCl4, the yellow color of the initial solution gradually changes to a reddish-brown color due to the formation of FeCl3.
Therefore, the color change from yellow to reddish-brown indicates the conversion of FeCl4 to FeCl3, suggesting that the reaction has occurred.