Question
Use the dissociation reaction to answer the question.
FeSCN2+(aq)⇋ Fe3+(aq)+SCN−(aq)
In the reaction, FeSCN2+ ions are red, Fe3+ ions are pale yellow, and SCN– ions are colorless.
A solution at equilibrium is yellow-orange. The concentration of SCN– ions is increased by a moderate amount. Which color will the solution most likely become?
(1 point)
Responses
colorless
colorless
orange
orange
red
red
yellow
FeSCN2+(aq)⇋ Fe3+(aq)+SCN−(aq)
In the reaction, FeSCN2+ ions are red, Fe3+ ions are pale yellow, and SCN– ions are colorless.
A solution at equilibrium is yellow-orange. The concentration of SCN– ions is increased by a moderate amount. Which color will the solution most likely become?
(1 point)
Responses
colorless
colorless
orange
orange
red
red
yellow
Answers
GPT-4o mini
To analyze the effect of increasing the concentration of SCN⁻ ions on the equilibrium of the reaction:
\[ \text{FeSCN}^{2+}(aq) \rightleftharpoons \text{Fe}^{3+}(aq) + \text{SCN}^-(aq) \]
we can apply Le Chatelier's principle, which states that if a change is made to a system at equilibrium, the system will adjust to counteract that change.
By increasing the concentration of SCN⁻ ions, the equilibrium will shift to the right to reduce the concentration of SCN⁻ ions. This means that more FeSCN²⁺ will dissociate into Fe³⁺ and SCN⁻.
Since:
- FeSCN²⁺ is red,
- Fe³⁺ is pale yellow,
- SCN⁻ is colorless,
the shift to the right results in the formation of more yellow (from Fe³⁺) and potentially colorless (from SCN⁻) ions in relation to the decreased concentration of red FeSCN²⁺.
As these changes happen, the overall color of the solution, which is currently yellow-orange (due to the presence of both Fe³⁺ and a small amount of FeSCN²⁺), will likely become **more yellow/orange,** but since the equilibrium now favors the formation of Fe³⁺ and SCN⁻, the solution may appear less red and more yellow in color.
Therefore, among the options provided, the most likely outcome is:
**yellow**
\[ \text{FeSCN}^{2+}(aq) \rightleftharpoons \text{Fe}^{3+}(aq) + \text{SCN}^-(aq) \]
we can apply Le Chatelier's principle, which states that if a change is made to a system at equilibrium, the system will adjust to counteract that change.
By increasing the concentration of SCN⁻ ions, the equilibrium will shift to the right to reduce the concentration of SCN⁻ ions. This means that more FeSCN²⁺ will dissociate into Fe³⁺ and SCN⁻.
Since:
- FeSCN²⁺ is red,
- Fe³⁺ is pale yellow,
- SCN⁻ is colorless,
the shift to the right results in the formation of more yellow (from Fe³⁺) and potentially colorless (from SCN⁻) ions in relation to the decreased concentration of red FeSCN²⁺.
As these changes happen, the overall color of the solution, which is currently yellow-orange (due to the presence of both Fe³⁺ and a small amount of FeSCN²⁺), will likely become **more yellow/orange,** but since the equilibrium now favors the formation of Fe³⁺ and SCN⁻, the solution may appear less red and more yellow in color.
Therefore, among the options provided, the most likely outcome is:
**yellow**