Question

how could the  purity of ethanol collected be checked?

Answer 1

Thank you for asking the question!
The purity of the ethanol can be tested in various ways. The content of  ethanol must be clear and colorless. Then it must has a pleasant odor. One must know the specific gravity of ethanol which is 0.185 at 68 degrees Fahrenheit. The apparatus like, the flask and thermometer while using ethanol must be clean. By keeping these precautions in mind you can check  the purity of ethanol. 
I hope it helps.