Am doing a lab report on the determination of the product of a redox reaction: the reaction of bromate and hydroxylammonium ions.
here is the lab
Experiment:
In this experiment you will determine the equation of a redox reaction by the use of experimental data.
This is a reaction in which it is not obvious what products will be formed but by finding the relative number of moles reacting
you can deduce what reaction has occured.
The reaction is between bromate ions, BrO3(-) and hydroxylammonium ions NH3OH(+) in aqueous acid solution.
You assume that the bromate are converted to bromide ions, Br(-) (How can this reaction be shoed experimentally)
So the reaction that is being studied is:
BrO3(-) + NH3OH(+) ----> Br(-) + ?
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If you know the number of moles of bromate consumed in the reaction and you know the oxidation states of Br in the reactant and in the product, then you can calculate the number of moles of electrons gained by Br in the reaction. (this must equal to the number of moles of electrons lost by the N of hydroxylammonium in the reaction. Knowing the number of moles of hydroxylammonium reacted, one can calculate the number of moles lost by N per hydoxylammonium reacted. This then allows you to determine the oxidation state of the N in the unknown product. In the acid solution, the following compounds of N and H and/or O can exist: NH4(+), N2H5(+), HN3, N2, N2O, NO, H2N2O3, HNO2, No2, No3(-).
It can be assumed that the N containing product of the reaction is one of these.
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The experiment is arranged so that the hydoxylammonium is the limiting reagent and bromate is in excess. The amount of this excess is found by adding potassium iodide solution, which reacts with bromate:
BrO3(-) + 9I(-) + 6H3O(+) ---> Br(-) + 3I3(-) + 9H20
You can assume that nothing else reacts with the iodide ions. The resulting triioxide ions, I3(-), are brown in colour and can be
titrated with thiosulphate, S2O3^2(-):
I3(-) + 2S2O3^2(-) ---> 3I- + S4O6^2(-)
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From the titration the number of moles of triiodide is determined. From the number of moles of triiodide and the two balanced equations above, the number of moles of excess bromate is determined. Subtracting the number of moles of excess bromate from the total number of moles of bromate used, gives us the number of moles of bromate consumed in the reaction. From this the N containing product can be identified and a balanced equation
for this reaction can be written.
i really don't understand what they talking about here really...i did the experiment and it was easy enough but i cant write a lab report... can sumone help me write out the purpose of this experiment. i wud really appreciate it.
It appears to me that the purpose of the experiment is in the first paragraph or two. Here is what I copied from your post.
In this experiment you will determine the equation of a redox reaction by the use of experimental data.
The purpose of this experiment is to determine the product of a redox reaction between bromate ions (BrO3-) and hydroxylammonium ions (NH3OH+). The reaction is conducted in an aqueous acid solution, and the goal is to figure out what product is formed when bromate ions are converted to bromide ions (Br-).
To achieve this, the experiment is designed to find the relative number of moles reacting, which will help deduce the reaction that occurred. By calculating the number of moles of electrons gained by bromine in the reaction and equating it to the number of moles of electrons lost by nitrogen in hydroxylammonium, the oxidation state of the nitrogen in the unknown product can be determined.
To start the experiment, hydroxylammonium is used as the limiting reagent, and bromate is intentionally in excess. The excess bromate is then reacted with potassium iodide solution. This reaction produces bromide ions (Br-) and triiodide ions (I3-), which can be easily detected due to their brown color. The triiodide ions are then titrated with thiosulfate (S2O3^2-) to determine their number of moles.
From the number of moles of triiodide and the balanced equations, the number of moles of excess bromate can be determined. Subtracting this from the total number of moles of bromate used gives the number of moles of bromate consumed in the reaction.
By identifying the nitrogen-containing product based on the calculated number of moles and the known compounds of N and H/O in an acid solution, a balanced equation for the reaction can be written.
Overall, the purpose of this experiment is to determine the unknown product formed in the redox reaction between bromate ions and hydroxylammonium ions by analyzing the number of moles of electrons lost and gained, and calculating the number of moles of bromate consumed.
Certainly! The purpose of this experiment is to determine the equation of a redox reaction between bromate ions (BrO3(-)) and hydroxylammonium ions (NH3OH(+)) in aqueous acid solution. In this reaction, it is not immediately clear what the products will be. However, by analyzing the relative number of moles reacting, it is possible to deduce the reaction that has occurred.
To start, you assume that the bromate ions are converted to bromide ions (Br(-)) in the reaction. The main goal of the experiment is to find a way to experimentally show this conversion.
To achieve this, the experiment is set up in such a way that hydroxylammonium is the limiting reagent and the bromate is in excess. To determine the amount of excess bromate, potassium iodide solution is added, which reacts with bromate according to the following equation:
BrO3(-) + 9I(-) + 6H3O(+) ---> Br(-) + 3I3(-) + 9H2O
This reaction forms brown triiodide ions (I3(-)), which can be titrated with thiosulphate (S2O3^2(-)). From the titration, the number of moles of triiodide can be determined.
By using the balanced equations given above, the number of moles of excess bromate can be calculated from the number of moles of triiodide. Subtracting the number of moles of excess bromate from the total number of moles of bromate used gives the number of moles of bromate consumed in the reaction.
With this information, it becomes possible to determine the N-containing product of the reaction and write a balanced equation for the reaction.
The overall purpose of this experiment, therefore, is to investigate and determine the equation for the redox reaction between bromate ions and hydroxylammonium ions by analyzing the relative number of moles reacting and using the concept of oxidation states and electron transfer.