What are the advantages and disadvantages of using alcohol in a thermometer liquid?

Answer 1

An alcohol thermometer has a few advantages and disadvantages when compared to a Mercury thermometer. It really depends on what you need to determine the temperature of and the resources you have available to you.

First of all, there are many kinds of alcohol that differ by their molecular formula. Methyl alcohol, or Methanol,is the "simplest" of these having only 1 Carbon atom. As atoms of Carbon are added to the molecular chain, the type of alcohol changes. An alcohol with 2 Carbon atoms is Ethanol -- the kind of alcohol found in beer and other liquors. In general an "alcohol" has the molecular formula CnH2n+1OH.

Its important to know what kind of alcohol is in your thermometer because the chemical properties of each one are different. In this case the most important property to you is the melting point and the boiling point of the alcohol.

Lets just say you have Ethanol in your thermometer, the melting and boiling points of which are about -114ºC and 78ºC respectively. For comparison, the melting and boiling points of Mercury are -39ºC and 357ºC. This means that mercury is going to freeze before ethanol does and ethanol is going to boil into a gas before mercury does.

So if you want to measure something really cold then you should use an alcohol thermometer -- but make sure it's not colder than -114ºC or else the ethanol will freeze, expand and possibly break your thermometer. Likewise if you want to measure something really hot (but not hotter than 357ºC) then use the mercury thermometer.

Mercury is harder to find and more expensive than ethanol so if you just need to measure something like the air temperature outside you should probably just use an ethanol thermometer. But if you need to measure something that can get really hot, like the temperature of a car's engine then spend the extra cash and get a mercury thermometer.

There's a number of other important differences between alcohols and mercury. Mercury is extremely toxic, alcohol is psychoactive if ingested in large quantities, alcohol is flammable, etc. The main things to consider about the two substances is their chemical properties and their economic efficiency.

Answer 2

Advantages;alcohol expands with increase in temperature.it also has a low melting point. Disadv:1.alcohol has a low boiling point of 78`c so cannot used to measure high temps.2.it has no visible colour so readings cannot be taken accurately

Answer 3

Advantages: Alcohol has a wide temperature range, is non-toxic, and less hazardous compared to mercury.

Disadvantages: Alcohol has a lower boiling point than mercury, making it less suitable for high-temperature applications. It also has a lower thermal conductivity and can evaporate more easily compared to mercury.

Answer 4

They are cheaper an they don't pose the same environmental risks when broken.

Answer 5

it is cheap