The indication from which one can determine how much of active ingredient is recovered after purification method is said to be a percent recovery.
The formula for percent recovery is:
[tex]Percent recovery = \frac{weight of substance after crystallization}{weight of substance used initialy}[/tex]
The solubility of acetanilide in 100 ml of chloroform at [tex]0^{o} C = 3.53 g[/tex]
The solubility of acetanilide in 100 ml of chloroform at [tex]60^{o} C = 29.1 g[/tex]
[tex]weight of acetanilide after crystallization = 29.1 g - 3.53 g = 25.57 g[/tex]
[tex]weight of acetanilide used initially = 29.1 g[/tex]
Substituting the values in the above formula:
[tex]Percent recovery = \frac{25.57}{29.1}\times 100[/tex]
[tex]Percent recovery = 87.869[/tex] %.
Hence, the maximum percent recovery that can be achieved for the recrystallization of acetanilide from chloroform is [tex]87.869[/tex] %.