Chemistry Notes: Lab & Atomic Structure Review
Lab Experiment Discussion: Hydrated Magnesium Sulfate Dehydration
- Experiment Objective: The primary goal was to dehydrate hydrated magnesium sulfate (\text{MgSO}{4} \cdot x\text{H}{2}\text{O}) by heating to determine the water of crystallization, potentially leading to the calculation of its empirical formula.
- Previous Experiment Context: An earlier experiment involved the combustion of magnesium ribbon, aiming to produce magnesium oxide (\text{MgO}). This previous result was cited as approximately \text{MgO}_{0.6} compared to the expected \text{MgO}.
- Methodology and Precautions:
- Pre- and Post-Heating Weighing: Crucial to wait before and after heating to ensure accurate mass measurements, as impurities or residual heat can affect the scale reading.
- Impurity Removal: All substances not involved in the reaction must be removed or accounted for to ensure precise mass readings, as they would add to the measured weight.
- Potential Experimental Difficulties & Impact on Results:
- Loss of Substance: If some of the substance (e.g., magnesium sulfate or water vapor carrying small particles) escapes from the crucible during heating or lifting (especially if spitting occurs and the lid is not closed), this will significantly affect the results.
- Consequence of Loss: The primary aim is to accurately determine the mass of water lost. If substances escape, the calculated mass of water lost will be inaccurate, leading to an incorrect empirical formula for the hydrated salt.
- Spitting: While spitting was noted, the closed lid of the crucible was intended to mitigate this issue, preventing significant loss.
- Result Discrepancies: The experimental results (\text{MgO}_{0.6} for magnesium combustion) were described as
