Recrystalization and Melting Points lab Ended up with no crop B... (do you want
ID: 891622 • Letter: R
Question
Recrystalization and Melting Points lab
Ended up with no crop B...
(do you want to see a pre-lab because I, myself had trouble doing and understand this lab?)
a. How different is the solubility of salicylic acid and adipid acid in water?
b. In your procedure you are asked to bring your dissolved mixture to room temperature and collect a solid before you drop the remaining liquid temperature to 0oC. Knowing you have a mixture of compounds with different solubility, why do you think it was done? what would happen if the whole dissolved compounds were put in an ice bath at 0oC?
c. Without looking into your MP results yet, and based on table for MP/identity of crop A&B, what is the identity (expected) for crop A and crop B?
d. How do your measurements of MP support the identification of Crop A and Crop B?
e. What does your MP measurements tell you about the purity of your Crop A and Crop B?
f. Calculate the recover yield for your recrystallization (Crop A and Crop B)
g. what does the recover yield tell you about the loss of your compounds?
h. What are the general sources of loss of your compounds in this experiment? Describe how/where you believe your losses happened and how to improve the loss in future experiments
crop MP crop mixed MP with salicylic acid mixed MP with adipic acid identity of crop A 157-160 158-161 145-149 salicylic acid B -- --- --- ---Explanation / Answer
a) due to difference in the intermolecular attaractions. There is a difference in M.P
b) at cold conditions, the intermolecular attractions will be created between the molecules and it forms sharp crystals in pure form.
c) if we compare both M.P, the crop with greater M.P is adipic acid and crop A with lower M.P is salicylic acid.
d) after measuring compare the experimetal values with known M.P values to get the results.
e) because of not similar values with known values, we conclude that impurities are there in the compounds.
f) % of purity = obtained crop A after recrystalization / before recrystallization)*100
g) If recover yield is greater ?% than loss % is less.
h) The loss may be in collecting compound from filtration or measuring weight of compounds.
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.