Lab report - Determine the Empirical Formula of Magnesium Oxide by reacting a known mass of Magnesium with Oxygen.

Quantitative data:

*(Uncertainty determined from the last decimal place of the electronic balance)

Processed Data

Calculations:

MgO = 41.5(+/- 0.1g) - 39.8(+/-0.1g) = 1.7(+/-0.2g)

Oxygen = 1.7(+/-0.2g) - 1.5(+/-0.1g)= 0.3(+/- 0.3g)

Deducing the Empirical Formula.

Empirical Formula: Mg10O3

Evaluation

Conclusion:

Mg10O3 is the empirical formula we found through our experiment. Theoretically, the empirical formula is MgO. This is because Magnesium is a group 2 element so it would lose two electrons to form Mg2+ ion. Oxygen is a group 6 element so it would gain two electrons to form a O2- ion. So in theory, the empirical formula is MgO. Therefore we see were nowhere close obtaining a empirical formula to the theoretical answer though according to our uncertainty for Oxygen which is ±3 it could be the oxygen we had weighed 5g and so therefore giving us a much accurate result of Mg10O2 which would go to a simplest ratio of Mg2O which would be closer to the theoretical answer. In addition to this according to our huge uncertainty the ratio could have also been 1:1 if the ratio would have led to 6:6. Though we see that the reason behind getting such an inaccurate answer is due to the incomplete combustion and due to not using a much more precise and accurate balance to weigh the apparatus and chemicals used.