Could someone check my answers?
1. Why was 95% ethanol alcohol added when titrating aspirin in an experiment?
Because it helps the aspirin dry quicker and become pure while the titration is going on.
2. Would the following mistakes cause the calculated percent yield to be higher, lower, or the same as the actual percent yield? Explain.
a) The aspirin was not completely dry before weighing the product.
A: The percent yield would be lower because the aspirin would fall apart and stick to the watch glass.
b) Room temperature, not chilled, distilled water was used.
A: The percent yield would be lower because the test tube with the aspirin would not crystallize and the experiment would fail.
c) When the students weighed the salicylic acid, some of it missed the Erlenmeyer flask and fell onto the balance pan without them knowing it.
A: The percent yield would not change because the acid was not used in the experiment yet.
d) Less than the calculated amount of aetic anhydride was used.
A: The percent yield would be lower because less of the aspirin would be produced than expected.
I am being blunt but my remarks are well intentioned. And I mean no offense. However, I think most of your answers fall into the category of "I don't know the answer but I must write something." The answers are gibberish except for the answer to (d).
I apologize if my previous answers were not clear or helpful. Allow me to explain the correct approach to checking your answers.
1. Why was 95% ethanol alcohol added when titrating aspirin in an experiment?
To determine the purpose of adding 95% ethanol alcohol during the titration of aspirin, it is important to have a clear understanding of the experiment. In this case, ethanol alcohol is typically used to dissolve the aspirin and any impurities present. This ensures that the solution is homogenous, allowing for an accurate titration. The ethanol also helps to facilitate the reaction during the titration process. As for drying the aspirin, it is not the primary purpose of adding ethanol, but the solvent does aid in evaporating any remaining moisture.
Now, let's proceed to the mistakes that could affect the calculated percent yield:
a) The aspirin was not completely dry before weighing the product.
Your initial response suggested that the percent yield would be lower because the aspirin would fall apart and stick to the watch glass. However, this response does not accurately address the question. The moisture content in the aspirin does not directly affect the percent yield. Rather, it may influence the accuracy of the mass measurement for calculating the yield.
b) Room temperature (not chilled) distilled water was used.
Your initial answer mentioned that the percent yield would be lower because the test tube with the aspirin would not crystallize. However, this answer is not correct. The temperature at which distilled water is used does not directly impact the percent yield. Distilled water is commonly used because it does not introduce additional impurities that could affect the reaction.
c) When the students weighed the salicylic acid, some of it missed the Erlenmeyer flask and fell onto the balance pan without them knowing it.
Your initial answer stating that the percent yield would not change because the acid was not used in the experiment is partially correct. When salicylic acid misses the Erlenmeyer flask, it is indeed not used in the reaction, meaning it would not directly influence the percent yield. However, it is important to note that any loss of reactant during the weighing process could indirectly affect the overall yield calculation.
d) Less than the calculated amount of acetic anhydride was used.
Your answer stating that the percent yield would be lower because less aspirin would be produced than expected is correct. If a smaller amount of acetic anhydride is used than what is calculated, it means that the limiting reactant quantity is insufficient. Consequently, a lower amount of aspirin would be produced, resulting in a lower percent yield compared to the theoretical value.
To summarize, answers (a) and (b) are not accurately addressing the impact on percent yield, while answers (c) and (d) correctly identify the potential effects. It is important to thoroughly understand the concepts and processes involved in the experiment when checking your answers to ensure accuracy.