How would you minimise these gravimetric analysis errors?

[man0005]

Homework Statement

-precipitate not being pure e.g. other ions (present in the precipitate increasing the weight of the precipitate)
- in an experiment where BaSO4 is used and some of it isn't dissolved in the wash due to the 'low solubility' of BaSO4 - resulting in a lower weight, decreasing the percentage by mass of the precipitate.
-impurities in the sample

Homework Equations

The Attempt at a Solution

 

[Borek]

-precipitate not being pure e.g. other ions (present in the precipitate increasing the weight of the precipitate)

Sometimes called coprecipitation.

in an experiment where BaSO4 is used and some of it isn't dissolved in the wash due to the 'low solubility' of BaSO4 - resulting in a lower weight, decreasing the percentage by mass of the precipitate.

No idea what you mean.

impurities in the sample

How is it different from the first point?

But, it is up to you to try to solve the question. So, how do you propose to minimize errors?

 

[man0005]

with the co precipitation
since I am finding the amount of sulfur in a samle of fertiliser
Since the sample is non homogenous, you could get samples from the bottom, top and middle of the fertiliser and test them? Then average them out?
Could you please help me elaborate on that/explain it a little better ><

 

[Borek]

Sorry, I have no idea what you are asking about.

Methodology of taking samples has nothing to do with coprecipitation.

 

[DeeNos]

To minimize these gravimetric analysis errors, several steps can be taken. Firstly, it is important to ensure that the precipitate is as pure as possible. This can be achieved by carefully selecting the reagents used and ensuring they are of high purity. Additionally, proper filtration and washing techniques should be employed to remove any impurities that may be present in the precipitate.

In the case of BaSO4, which has low solubility, it is important to ensure that the precipitate is completely dissolved in the wash solution. This can be achieved by using hot wash solutions and ensuring sufficient time for the precipitate to dissolve. It may also be helpful to use a chelating agent, such as EDTA, to prevent the formation of insoluble BaSO4 complexes.

To address the issue of impurities in the sample, it is important to properly prepare and handle the sample before analysis. This may involve purification techniques such as acid digestion or sample dilution. It is also important to carefully control the experimental conditions, such as temperature and pH, as these can affect the formation and purity of the precipitate.

In addition to these steps, it is important to carefully monitor and document all experimental procedures to ensure consistency and accuracy. Any deviations or errors should be noted and addressed immediately. Regular calibration of equipment and use of appropriate standards can also help to minimize errors in gravimetric analysis.

Overall, minimizing gravimetric analysis errors requires careful attention to detail, proper selection and handling of reagents and samples, and consistent and accurate experimental procedures. By taking these steps, the accuracy and reliability of the gravimetric analysis can be greatly improved.