A flask contains this equilibrium
Fe3+(aq) + SCN1-(aq) <======> FeSCN1-(aq)
What is observed if a few drops of iron(II) chloride is added to this equilibrium?
a it becomes darker red
b it becomes lighter red none of the above
c it becomes colourless
d. nothing happens
e. none of the above
Are you SURE the equation you wrote is correct. Is that REALLY FeSCN^- and not FeSCN^+2
The answer here is nothing happens because you are adding Fe 2+ but in the equations yo are using Fe 3+
The addition of iron(II) chloride to the equilibrium will not cause any change. Therefore, the correct answer is d. nothing happens.
To determine what happens if a few drops of iron(II) chloride is added to the given equilibrium, we need to consider the effect iron(II) chloride has on the equilibrium.
Iron(II) chloride, written as FeCl2, contains iron(II) ions (Fe2+). In the given equilibrium, we have Fe3+ ions present. When Fe2+ ions are added, they can react with the SCN- ions to form FeSCN2+ ions.
Fe2+(aq) + SCN1-(aq) ------> FeSCN2+(aq)
This reaction consumes Fe2+ ions and SCN- ions, thus removing them from the equilibrium mixture. As a result, the system tries to restore equilibrium by shifting the reaction in the forward direction to produce more SCN- ions. This leads to the formation of more FeSCN1- ions.
Fe3+(aq) + SCN1-(aq) <======> FeSCN1-(aq)
Since the reaction produces more FeSCN1- ions, which are responsible for the red color in the equilibrium, the addition of iron(II) chloride results in the solution becoming darker red. Therefore, the correct answer is option a: it becomes darker red.