Melting point was 131.4 6. If a percent yield is lower than 100%, what factors c
ID: 1034944 • Letter: M
Question
Melting point was 131.4 6. If a percent yield is lower than 100%, what factors could account for it? If a percent yield is higher than 100%, what factors-could account for it? NOTE: You need to answer both parts of this question regardless of whether your own % yield was high or low. 7. The expected melting point range for acetyl salicylic acid is 138-140°C. State the melting point range for your crude acetyl salicylic acid product and compare it to the expected value. Explain why you believe the values are different, similar, etc. Why is the melting "point" reported as a range instead of a single number?
Explanation / Answer
6.) percentage yield =actual yield / theoretical yield *100%
7.the m.p of the crude sample is lesser than the actual m.p range. This is because of the presence of impurities in the crude sample. Impurities occupies the lattice sites and blocks their formation and causes irregularities. This weakens the intermolecular bonds and hence low energy is required to break the bonds. Therefore the m.p becomes lower.
If the m.p of crude sample is higher, it may because tha m.p of the impurity is much higher than the acetyl salicylic acid.
This can also be happen if the sample and the impurities form azeotropic mixture with low m.p than the pure compound.