Are alcohol thermometers better than mercury thermometers?
They both have advantages and disadvantages:
A mercury-in-glass thermometer can measure high temperature (up
to 357 0C, the boiling point of mercury; and its freezing point is
-39 0C).
An alcohol-in-glass thermometer can measure low temperature
(down to -115 0C, the freezing point of alcohol; and its boiling
point is 78 0C.)
A mercury-in-glass thermometer can quickly response to
temperature, while an alcohol-in-glass thermometer can only slowly
response to temperature.
However, mercury is poisonous and alcohol is NOT poisonous. Also
mercury thermometers are not allowed on aircraft.