Laboratory Chemisry Question - Redox Reaction

[vertciel]

Homework Statement

1. Explain why the following chemical reaction would not be effective to determine [Fe²⁺] in a given solution.

Fe²⁺ _(aq) + H₂O_{2 (aq)}-> Fe³⁺ _(aq)+ H₂O_(l) | in acidic solution

Homework Equations

The Attempt at a Solution

Hello:

I am thinking that there may be a lack of colour change to indicate the stiochiometric endpoint of the redox reaction. I know that hydrogen peroxide and water are both clear and colourless in solution.

However, I do not know the colours of Fe²⁺ and Fe³⁺ in solution.

Thank you in advance!

 

[Borek]

Endpoint detection can be done with some instrumental method, so it should be not a problem (although listing it won't hurt). However, what do you know about hydrogen peroxide stability?

 

[Blueshift5]

I would like to provide a response to your question regarding the effectiveness of the given chemical reaction in determining [Fe2+] in a solution.

Firstly, the chemical reaction given is a redox reaction, which involves the transfer of electrons between the reactants. In this case, Fe2+ is oxidized to Fe3+ while H2O2 is reduced to H2O. The stiochiometric endpoint of a redox reaction is usually indicated by a change in color due to the formation of a colored product.

However, as you have correctly pointed out, both H2O2 and H2O are clear and colorless in solution, making it difficult to determine the endpoint of the reaction. Additionally, the colors of Fe2+ and Fe3+ in solution may not be easily distinguishable, making it challenging to accurately determine the amount of Fe2+ present.

Furthermore, in an acidic solution, the presence of H+ ions may interfere with the reaction, leading to inaccurate results. This is because H+ ions can also act as oxidizing agents, which may compete with H2O2 for electrons, resulting in incomplete or inaccurate oxidation of Fe2+ to Fe3+.

Therefore, it can be concluded that the given chemical reaction is not effective in determining [Fe2+] in a given solution due to the lack of a distinct color change and potential interference from H+ ions. Alternative methods, such as titration or spectrophotometry, may be more suitable for accurately determining the concentration of Fe2+ in a solution.