Alcohol, which is used as a thermometric liquid, has the following characteristic properties :
1. Alcohol has a very low freezing point of about −112oC and hence is suitable in thermometers to record very low temperatures.
2. Alcohol has a low boiling point of about 78oC and therefore cannot be used to measure high temperatures.
3. Alcohol can be colored brightly (by adding a dye, generally red) and then it is clearly visible through glass.
4. Alcohol expands more than mercury.
5. Alcohol is fairly inexpensive.
6. Alcohol wets glass.
7. Alcohol is not a good conductor of heat.
Hence alcohol thermometers are used.