Question

How would the following affect the purity, melting point and yield of your product? Write increase, decrease or no change. 12 pts.

You had a significant amount of aspirin contaminating your final product.

Purity:                                       Melting point:                                        Percent yield:                      

Your unknown was acetanilide, but you somehow contaminated it with phenacetin.

Purity:                                       Melting point:                                        Percent yield:    

You inadequately dried your unknown.

Purity:                                       Melting point:                                        Percent yield:                      

You used an excessive amount of water to recrystallize your product.

Purity:                                       Melting point:                                        Percent yield:

Answer 1

1. when a significant amount of aspirin contaminating final product,

Purity: Decreases

Melting point: Decreases

Percentage yield: Increases

2. When unknown was acetanilide, but somehow contaminated with phenacetin,

Purity: Decreases

Melting point: Decreases

Percentage yield: increases

3. Sample was inadequately dried

Purity: No change

Melting point: Increases

Percentage yield: Increases

4. When an excessive amount of water was used to recrystallize the product,

Purity: Increases

Melting point: Increases

Percentage yield: Decreases