Final answer:
The major sources of error in the determination of the molar mass can include measurement inaccuracies, impurities, not accounting for environmental variables, and instrumental calibration. To ensure precise results, it is crucial to mitigate these potential errors through meticulous planning and conducting of experiments.
Step-by-step explanation:
There are several major sources of error when determining the molar mass in chemical experiments. These include inaccuracies in weighing the substances, impurities in the chemicals used, and measurement errors in the volume of gases, if applicable. Additionally, errors may arise from not accounting for variables such as partial pressure of water vapor in gas collection methods or assuming the inaccurate purity of a substance.
For instance, when a reaction's product is a gas, if it is collected over water, the vapor pressure of water could cause the volume of the gas to be measured as greater than it actually is, leading to a lower calculated molar mass. Another example is if the scales used for measuring the mass are not calibrated correctly, or if the substance is hygroscopic and absorbs moisture from the air, which can increase the weight measured and skew results.
When working with boiling point elevation or freezing point depression to determine molar mass, the error can come from inaccurate temperature readings or impurities in the solvent which affect its properties. To improve the accuracy of experimental findings, these potential sources of error should be minimized through careful experimental design and execution.