Part i. you considered the equilibrium: fe3+(aq) + scn-(aq) fe(scn)2+(aq), and compared the color of the solutions in four test
tubes. in the third test tube, you added 6 m naoh dropwise. how do you explain the formation of a precipitate and the shift in equilibrium in terms of lechatelier's principle?
The equilibrium will be shifted to lift with the formation of a brown gelatinous precipitate of Fe(OH)₃.
Explanation:
Le Chatelier's principle states that <em>"when any system at equilibrium for is subjected to change in concentration, temperature, volume, or pressure, then the system readjusts itself to counteract the effect of the applied change and a new equilibrium is established that is different from the old equilibrium"</em>.
The addition of NaOH will result in the formation of Fe(OH)₃ precipitate which has a brown gelatinous precipitate.
The formation of this precipitate cause removal and decrease of Fe³⁺ ions.
According to Le Chatelier's principle, the system will be shifted to lift to increase Fe³⁺ concentration and reduce the stress of Fe³⁺ removal and readjust the equilibrium again. So, the [Fe(SCN)²⁺] decreases.
Increasing [Fe³⁺] will produce a yellow color solution that contains a brown gelatinous precipitate of Fe(OH)₃.
