Question

Extraction of Trimyristin from Nutmeg Lab

1. Why is acetone a good solvent to recrystallize the trymyristin? What are the disadvantages?

2. Assume that the amount of trimyristin in nutmeg is 20% by weight. What would be the expected amount to be recovered from the 7.00g of nutmeg?

3. Calculate your percent recovery using the expected recovery amount (expected 20% of the sample you weighed).

4.If the melting point of the purified trimyristin was done before it was completely dry what would be the effect on the melting point and why?

Answer 1

1.)

Acetone is the recrystallization solvent used to purify the crude trimyristin .Trimyristin is highly soluble in ether at room temperature thereby making ether a poor choice for a recrystallization solvent. In acetone, trimyristin is "soluble hot, insoluble cold.". Disadvantage is that it is trimystin is soluble in hot acetone.

2.)

amount of trimyristin in nutmeg = 20% w/w

mass of nutmeg = 7.00 g

Expected amount to be recovered = 20% of 7 g = 1.4 g

3.)

Expected recovery amount = 1.4 g

Recovery = 20% 0f 1.4 g = 0.28 g

Percent recovery amount = (0.28/7) * 100 = 4 %

4.)

The melting point may or may not be affected. Melting points are dependent on the intermolecular binding of a compound. If a sample contains water and the melting point is much higher than the boiling point of water, the water may evaporate and no change in the melting point will be observed. This is similar to a sample containing, glass, oxygen or nitrogen. They do not alter the intermolecular forces of the sample. However, if the sample melting below the boiling point of water, then water may act as a solvent and dissolve and melt a sample thus reducing its melting point.

Here, melting point of trimyristin = 56–57 °C

Melting point of water = 0 °C

So, here the melting point of trimyristin will decrease than 56-57  °C. It will not give accurate result.