During your experiment, you are drive water from the hydrate MxXy*zH2O. You subsequently determine that your hydrate has six molecules of waters associated with each formula unit. However, the bottle the hydrate came from indicated a formula with only four molecules of water. What went "wrong" in your experiment?
All I can think of is the bottle could be mismarked.
That is real confidence in your lab skills to suggest it couldn't be your fault. But I think the spirit of the question is for you to suggest what YOU did wrong, as well.
a. Heating the sample drove off all the water but also decomposed the sample, making the weight loss too high.
b. The bottle was mislabeled (your original answer).
These two may help get you started.
I think the answer is that the bottle of compounds were previously opened, thus altering the water content.
Yes, you are correct. The most likely explanation for the difference between the experimentally determined six water molecules per formula unit and the four water molecules indicated on the bottle is that the bottle was mismarked. In other words, the label on the bottle did not accurately represent the composition of the hydrate. This could have been a simple error during labeling or a mistake made during the manufacturing or packaging process. To confirm this, it would be beneficial to double-check the experimental procedure and perform further analyses to ensure the accuracy of the results.
In your experiment, you found that the hydrate MxXy*zH2O actually has six molecules of water associated with each formula unit, while the bottle indicated a formula with only four molecules of water. There are a few possible reasons for this discrepancy:
1. Measurement error: It is possible that there was an error in the measurement during your experiment, leading to a higher determination of water molecules. Double-check your experimental procedure and calculations to ensure accuracy.
2. Impurities: Sometimes, hydrate compounds can contain impurities that can affect the water content. If the hydrate you used had impurities, it could have resulted in a higher water content than indicated on the bottle.
3. Different hydrate form: It is also possible that there are different forms or types of the hydrate MxXy*zH2O, each with varying amounts of water molecules. The bottle you used might have contained a different form of the hydrate, one with only four molecules of water, while the one you tested had the form with six molecules of water.
To resolve this, you could repeat the experiment using a different sample of the hydrate, preferably from a reliable source, to verify the water content. Additionally, you can consult scientific literature or reputable sources to gather information about the hydrate's known forms and their respective water content. This will help ensure accuracy and provide a better understanding of the hydrate compound you are working with.