The boiling point of alcohol is 78°C while that of water has not uniform rate of expansion and it vaporizes easily when temperature increases that makes difficult on reading.
The liquid used can be pure ethanol, toluene, kerosene or isoamyl acetate, depending on manufacturer and working temperature range. Since these are transparent, the liquid is made more visible by the addition of a red or blue dye.The alcohol thermometer or spirit thermometer is an alternative to the mercury-in-glass thermometer and has similar functions. Unlike the mercury-in-glass thermometer, the contents of an alcohol thermometer are less toxic and will evaporate quickly.
Alcohol thermometers are also inexpensive and durable. They are typically not as accurate as mercury thermometers because of the alcohol's susceptibility to evaporation, polymerization potential and capillary separation. Their primary advantage is safety to humans and the environment.So, alcohol, which freezes at temperature below the point where water freezes, was used. The red colored or silver line in the middle of the thermometer moves up and down depending on the temperature. The thermometer measures temperatures in Fahrenheit, Celsius and another scale called Kelvin.
An alcohol thermometer cannot be used to measure the temperature of boiling water . ... Alcohol thermometers are used rather than mercury thermometers in very cold regions because alcohol has a lower freezing point than mercury. Pure ethanol freezes at -115 degrees C, while mercury freezes at -38 degrees C.No. Alcohol starts boiling at 80∘C while boiling point of mercury is 357
It is an alternative to the mercury-in-glass thermometer and has the same functions. The contents of alcohol are less toxic and will evaporate quickly as compared to the mercury-in-glass thermometer. ... Therefore, No alcohol thermometer cannot be used to measure the temperature of boiling water.