Determine BaCl2.2 H2O -Gravimetric Analysis Lab

Mass of Barium Chloride after 2nd Heating:

28.38 ± 0.01g (Mass of Crucible, Lid and Heated Barium Chloride after 2nd heating) – 26.64 ± 0.01g (Mass of Crucible and Lid) = 1.74 ± 0.02g (Mass of Barium Chloride after 2nd Heating)

Mass of Barium Chloride after 3rd Heating:

28.38 ± 0.01g (Mass of Crucible, Lid and Heated Barium Chloride after 3rd heating) – 26.64 ± 0.01g (Mass of Crucible and Lid) = 1.74 ± 0.02g (Mass of Barium Chloride after 3rd Heating)

Mass of Water Removed from Barium Chloride on 1st Heating:

28.65 ± 0.01g (Mass of Crucible and Lid and Barium Chloride Sample) – 28.38 ± 0.01g (Mass of Crucible, Lid and Heated Barium Chloride after 1st heating) = 0.27 ± 0.02g (Mass of water removed from Barium Chloride on 1st Heating)

Mass of Water Removed from Barium Chloride on 2nd Heating:

28.65 ± 0.01g (Mass of Crucible, Lid and Barium Chloride Sample) – 28.38 ± 0.01g (Mass of Crucible, Lid and Heated Barium Chloride after 2nd heating) = 0.27 ± 0.02g (Mass of water removed from Barium Chloride on 2nd Heating)

Mass of Water Removed from Barium Chloride on 3rd Heating: 

28.65 ± 0.01g (Mass of Crucible and Lid and Barium Chloride Sample) – 28.38 ± 0.01g (Mass of Crucible, Lid and Heated Barium Chloride after 3rd heating) = 0.27 ± 0.02g (Mass of water removed from Barium Chloride on 3rd Heating)

Number of Moles of Barium Chloride:

1.67 ± 0.02 g/ 208.24 gmol- = 0.01 mol

[Mass of anhydrous Barium Chloride after Constant Mass is Achieved DIVIDED (/) by Molar Mass of Barium Chloride = Number of Moles of anhydrous Barium Chloride in Experiment]

Number of Moles of Water Removed from Barium Chloride:

0.27 ± 0.02 g / 18.02 gmol- = 0.02 mol

[Mass of Water Removed from Barium Chloride after constant mass is achieved DIVIDED (/) by the Molar mass of water = Number of moles of water removed from Barium Chloride]

Consequently, the experimental ratio of Barium Chloride and Water in BaCl2.x H2O is 1:2. This is because when you divide each number of moles of water and barium chloride in the experiment by the smallest value – 0.01 it gives such a ratio

From this ratio we can establish the X value in this formula. Hence, it would be 2 due to the fact that we gathered from the ratio that there are 2 hydrogen molecules for every Barium Chloride. Therefore the full equation for hydrated barium chloride is BaCl2.2 H2O.

Conclusion

        From my research I have found out that the accepted value of hydrated barium chloride’s formula is BaCl2.2 H2O. Moreover, the formula that I have determined from the experiment is also BaCl2.2 H2O, which means that I have successfully accomplished in getting near to the theoretical formula of hydrated barium chloride

Evaluation

        Firstly, I would like to recognize two types of errors. First, the random errors: Random errors are unidentifiable and cannot be eliminated. The effect of random errors can be reduced by carrying out the investigation number of times.

         The second type of errors is the systematic errors. These errors are identifiable and can theoretically be eliminated. These occur due to the limitations of the equipment or method. They will occur no matter how many times the investigation is carried out and they allegedly distort the data in a particular direction.

         Possibilities for how we might have twisted our results might be, as I just mentioned, the accuracy of equipments. To be more specific, the weight could have been more sophisticated. The fact that it isn’t the best possible weight might have affected our experiment in a bad way because we dealt with small masses i.e. the 2g mass of hydrated barium chloride. See, the problem here is that it gets more risky when measured small amounts because it ends up having a higher probability of an error occurring. On the contrary, if I were to measure big amounts it wouldn’t have mattered as much as if I were to use small numbers because I constantly round the figures causing the experiment to be less accurate.         

        Another likelihood of something that might have distorted our results was that there could have still been a bit of un-evaporated water molecules on the barium chloride because they possibly might have been trapped underneath the sample unable to evaporate. Even, maybe, there might have been water molecules inside the sample that was too, unable to evaporate. In this case, I way to resolve this issue might be to crush the sample and reduce its surface area so that most or all the water evaporates.

        Additionally, one plausible reason to why all the water did not evaporate might be due to the fact that the flame was not heating the sample strong enough to evaporate all the water from the barium chloride. Thus strengthening the flame and using a pure blue flame might have helped make a more accurate experiment.         

        Another systematic error would be how impurities in the barium chloride might have altered the results. The barium chloride might have been impure to start off with. A way of approaching this issue would be to buy the sample from a famous or well known brand.

        Finally, the last issue that I would like to indicate before ending this report is another major factor that have might influenced my results. A possible inaccuracy of this experiment could be a result of dust forming on the crucible during the heating process by the flame. In this scenario, I utilized the blue flame from the Bunsen burner, which is less dirty than the yellow flame. Nevertheless, if dirt formed on the crucible its mass would be changed, hence, making results imprecise. Another possible circumstance where dirt could have been transferred is from the tongs. While lifting the tong, some dirt might have spilled on the crucible; again, this would certainly affect the mass of the crucible. This error would have been eliminated if clean tongs were to be used.