Correlate the observations with Le Chatelier's principle?

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In summary: Test tube 3: 25 drops of 6 M NaOH are added (the blood red color turns to yellow)The yellow color is due to the formation of the Fe(OH)3 precipitate which removes Fe3+ ions from solution, causing a shift to the left in the reaction.Test tube 4: more distilled water is added (the blood red color becomes lighter in appearance)As more water is added, the concentration of the reactants decreases, causing a shift to the left in the reaction. This results in a lighter appearance of the blood red color. In summary, the addition of 0.1 M Fe(NO3)3 and KSCN does not change the color of the solution in Test Tube
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imconfused
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(see image below) A solution made with 3mL of 0.1 M Fe(NO3)3, 3mL 0.1 M KSCN, and 35 mL of distilled water is poured into 4 test tubes. The color of the solution in each test tube is a blood red due to the formation of Fe(SCN)2+.

Test tube 1: a few drops of 0.1 M Fe(NO3)3 are added (the blood red color remains the same)

Test tube 2: a few drops of 0.1 M KSCN are added (the blood red color turns darker)

Test tube 3: 25 drops of 6 M NaOH are added (the blood red color turns to yellow)

Test tube 4: more distilled water is added (the blood red color becomes lighter in appearance)Okay, I'm confused when it comes to correlating my color observations of each test tube with Le Chatelier's principle. Test tube 1 and 2 throw me off because shouldn't they both turn darker because more Fe3+ and SCN ions are added which help produce more Fe(SCN)2+? Also, why does test tube 3 turn yellow, where does the yellow color come from? Test tube 4 is obvious because the concentration lessons. Please help, thanks you.

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When you add NaOH, the OH- ions combine with the Fe+3 ions to form a precipitate, Fe(OH)3, effectively removing the Fe+3 ions from solution. This causes the system to shift to the left, to replace the Fe +3 ions.
 
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imconfused said:
solution made with 3mL of 0.1 M Fe(NO3)3, 3mL 0.1 M KSCN

Test tube 1: a few drops of 0.1 M Fe(NO3)3 are added (the blood red color remains the same)

Think about stoichiometry of the reaction.

Test tube 2: a few drops of 0.1 M KSCN are added (the blood red color turns darker)

This system is much more complicated and FeSCN2+ is not the final product. All complexes up to Fe(SCN)63- are produced.
 

1. What is Le Chatelier's principle?

Le Chatelier's principle is a fundamental principle in chemistry that states when a system at equilibrium is subjected to a change, it will respond by shifting in a direction that minimizes the effect of that change.

2. What is the significance of correlating observations with Le Chatelier's principle?

Correlating observations with Le Chatelier's principle allows us to predict how a system at equilibrium will respond to changes in conditions such as temperature, pressure, or concentration. This understanding is essential in many chemical processes, such as industrial production and environmental systems.

3. How do you apply Le Chatelier's principle to a given set of observations?

To apply Le Chatelier's principle, you must first identify the equilibrium condition and the change that is being applied to the system. Then, you must determine which direction the equilibrium will shift in response to that change based on the principles of Le Chatelier. Finally, you can predict the resulting changes in the system.

4. Can Le Chatelier's principle be used to predict the exact outcome of a system at equilibrium?

No, Le Chatelier's principle can only predict the direction in which an equilibrium system will shift in response to a change. The exact outcome will depend on factors such as the magnitude of the change, the initial concentrations, and the equilibrium constant of the reaction.

5. Is Le Chatelier's principle applicable to all chemical systems?

Yes, Le Chatelier's principle is a universal principle that applies to all chemical systems at equilibrium. It is based on the fundamental principles of thermodynamics and can be used to predict the behavior of all chemical reactions, regardless of their complexity.

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