Question

In very cold countries the thermometric liquid used is alcohol because _____.
1. The freezing point is lower than that of mercury
2. The freezing point is higher than that of mercury
3. The boiling point is much higher than that of mercury
4. The boiling point is same as that of mercury

Answer 1

Correct Answer - Option 1 : The freezing point is lower than that of mercury

The correct answer is The freezing point is lower than that of mercury.

• The alcohol thermometer or spirit thermometer is an alternative to the mercury-in-glass thermometer and has similar functions.
• Mercury has a freezing point of -38.83 °C and hence in cold environment mercury will freeze and hence mercury thermometer won't be able to function. 
• On the other hand, the freezing point of alcohol is -114 °C and hence an alcohol thermometer will be able to work perfectly in comparatively colder environments.

Advantages and Disadvantages of Mercury Thermometer:

Advantages	Disadvantages
Cheap	The display is harder to read
Durable	Does not work below -38.83 °C
Accurate	Slow response
Easy Calibration	Mercury vapour is poisonous

Advantages and Disadvantages of Alcohol thermometer:

Advantages	Disadvantages
Lower freezing point (-114 °C)	Less durable (the alcohol evaporates)
Larger coefficient of expansion	Alcohol can polymerize
Less hazardous	Fluid loss by evaporation hard to avoid
	Lower boiling point (60 °C)