Maximum % yield after recrystallization?

[classicfan]

Hello.

 

I am having trouble with a question in my textbook.

 

If I have an 8.3 g sample of acetanilide (Solubility => 0.53g/100mL at 25oC and 5.0g/100 mL at 100oC) that needs to be purified by recrystallization, then what is the maximum % yield that can be recovered (10% excess of solvent was used)?

 

I'm confused as to how I go about such a question, so if you could, please, hint at what path I am supposed to take, I'd greatly appreciate it.

[hermanntrude]

first, figure out how much solvent was used at 100°C to dissolve the acetanilide. Then figure out how much acetanilide that quantity of solvent will dissolve at 25°C, subtract one from the other, then compare that quantity with your 8.3g to find the percent yield.