Question

Why are thermometers filled with alcohol instead for water?

Answer 1

Hello. Most thermometers would use mercury, but some use alcohol thanks to its freezing points. Alcohol freezes at -114 Celsius, while water freezes at 0 Celsius. If it was freezing outside, the water would freeze too, making the thermometer useless.

Answer 2

Most thermometers are filled with mercury, but some are filled with alcohol. The reason we use alcohol instead of water is that alcohol has a lower freezing point (-114°C) than water (0°C). 

Also, alcohol doesn't condensate on the top unlike water, which makes the reading of the thermometer easier to read.