When silver nitrate is added to the Fe/SCN equilibrium, why is the colorless intense and a precipitate forms?

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Answer:

Here's what I get  

Explanation:

You have an equilibrium reaction between Fe³⁺/ SCN⁻ and FeSCN²⁺.

[tex]\underbrace{\hbox{Fe$^{3+}$}}_{\text{pale yellow-green}} +\underbrace{\hbox{SCN$^{-}$}}_{\text{colourless}} \, \rightleftharpoons \, \underbrace{\hbox{Fe(SCN)$^{2+}$}}_{\text{deep blood red}} \\[/tex]

When you add AgNO₃, the Ag⁺ reacts with the SCN⁻. It forms a colourless precipitate of Ag(SCN).

Ag⁺(aq) + SCN⁻(aq) ⟶ AcSCN(s)

According to Le Châtelier's Principle, when we apply a stress to a system at equilibrium, the system will respond in a way that tends to relieve the stress.

If you add Ag⁺ to the equilibrium solution, it removes the SCN⁻ [as an Ag(SCN) precipitate].

The system responds by trying to replace the missing SCN⁻:

The Fe(SCN)²⁺ dissociates to form SCN⁻, so the position of equilibrium shifts to the left,

You now have more Fe³⁺ and SCN⁻ and less of the highly coloured Fe(SCN)²⁺ at the new equilibrium.

The deep red colour becomes less intense.

 

When silver nitrate is added to the Fe/SCN equilibrium,  the colourless intense and precipitate forms because it settles at the bottom.

What is chemical equilibrium?

Chemical equilibrium is the condition in the course of a reversible chemical reaction in which no net change in the amounts of reactants and products occurs.

The added silver nitrate, [tex]AgNO_3[/tex] , effectively removes thiocyanate ions, [tex]SCN^{-1}[/tex], from the equilibrium system via a precipitation reaction when the [tex]Ag^{+1}[/tex] combines with [tex]SCN^{-1}[/tex] to produce insoluble silver thiocyanate, AgSCN, which settles to the bottom of the test tube.

Ag⁺(aq) + SCN⁻(aq) ⟶ AcSCN(s)

According to Principle, when we apply stress to a system at equilibrium, the system will respond in a way that tends to relieve the stress.

Adding Ag⁺ to the equilibrium solution, it removes the SCN⁻ [as an Ag(SCN) precipitate].

The system responds by trying to replace the missing SCN⁻:

The Fe(SCN)²⁺ dissociates to form SCN⁻, so the position of equilibrium shifts to the left,

You now have more Fe³⁺ and SCN⁻ and less of the highly coloured Fe(SCN)²⁺ at the new equilibrium.

The deep red colour becomes less intense.

Learn more about chemical equilibrium here:

https://brainly.com/question/4289021

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