Introductory Physical science Question

Question

A student uses a home freezer in an experiment to find the freezing point of rubbing alcohol. The temperature reaches a plateau at -10 degrees Celsius but the alcohol doesn't freeze. How can you explain this result

Answer 1

Emma,

 

A home freezer does not get much colder than -10^oC.  That's why you reached a temperature plateau.  But rubbing alcohol doesn't freeze until the temperature drops to something around -117^oF  which your freezer never reaches.  So the rubbing alcohol didn't freeze.  

 

Remember, alcohols were mixed with water in car radiators in winter to prevent the cooling system from freezing up on icy cold days.