Question

To really evaluate the success of this synthesis, you will need to carefully consider both the purity and percent yield.

To say your experiment was a success and that you have made a reasonable amount of Fumaric acid, which of the following statements would you consider to be successful?

Fumaric acid has been successfully prepared if the percent yield is 90%, the melting point was 310-316oC and it was insoluble in water.
	Fumaric acid has been successfully prepared if the percent yield is 80%, the melting point was 130oC and it was soluble in water.
	Fumaric acid has been successfully prepared if the percent yield is 70%, the melting point was 270-272oC and some powder was seen when doing a solubility test in water.
	Fumaric acid has been successfully prepared if the percent yield is 40%, the melting point was 298-300oC and the powder was found to be insoluble in water.

Answer 1

Physical properties of fumaric acid:

1. white crystalline compound or white solid

2. Melting Point = 298 - 300⁰C

3. solubility in water = slightly soluble

now let's consider all statements one by one:

statement one says that the % yield is 90% and M.P. = 310 -316⁰C and insoluble in water. if we match this statement with the physical properties of fumaric acid than we can observe that the M.P. is greater than that of fumaric acid as well as it is insoluble in water therefore either the compound is not fumaric acid or contains more impurity, therefore, this is not the successful synthesis of fumaric acid

statement two says that the % yield is 80% and M.P. = 130 ⁰C and soluble in water. if we match this statement with the physical properties of fumaric acid than we can observe that the M.P. is very less that of fumaric acid therefore either the compound is not fumaric acid or contains more impurity, therefore, this is not the successful synthesis of fumaric acid

statement three says that the % yield is 70% and M.P. = 270 - 272 ⁰C and some powder is soluble in water. if we match this statement with the physical properties of fumaric acid than we can observe that the M.P. is somewhat less that of fumaric acid, therefore, the fumaric contains more impurity, therefore, this is not the successful synthesis of fumaric acid

statement four says that the % yield is 40% and M.P. = 298 - 300 ⁰C and is insoluble in water. if we match this statement with the physical properties of fumaric acid than we can observe that the M.P. is exactly matching with that of fumaric acid, therefore, the fumaric acid prepared is pure albeit in a low quantity, therefore, this is the successful synthesis of fumaric acid